Acknowledgements

I would like to acknowledge my mentors in the European Masters in Disaster Medicine who taught me a lot and allowed me to refer to their valuable lectures and articles on disaster medicine. I would also specially wish to thank my department and chairman who provided me with the needed time to finish the chapter.


*3.5. Distribution of C. xiaoi Subtype Families by Farm*

One to 10 subtype families were found on each farm. As shown in Table 1, three farms had only one subtype family, two farms had two, two farms had four, one farm had six, one farm had seven, and two farms had 10. On Farms 9, 10, and 11 in Guangdong, all *gp60* sequences obtained belonged to the subtype family XXIIIa. In contrast, although only eight samples were subtyped on Farm 4 in Qinghai, they belonged to four subtype families (XXIIId, XXIIIe, XXIIIh, and XXIIIi). In addition, co-infections of different subtype families were observed in animals on Farms 1, 3, 5, 6, and 7, mostly with prevalent subtype families on the farm (Table 1).

#### **4. Discussion**

In the present study, we conducted whole genome sequencing of *C. xiaoi* and identified its *gp60* gene. Based on the sequence data, we established a *gp60*-based subtyping tool to assess the genetic diversity of *C. xiaoi*. The application of this subtyping tool in the analysis of *C. xiaoi*-positive samples from various breeds of sheep and goats has identified high genetic diversity within the species and possible differences in the distribution of subtypes between the two types of hosts.

The *gp60* gene sequence of *C. xiaoi* is highly divergent from that of other *Cryptosporidium* spp. Similar to the *gp60* gene of *C. ryanae* (~1548 bp), the *C. xiaoi gp60* gene (~1437 bp) is much longer than those in *C. parvum*, *C. hominis*, and *C. ubiquitum* (~873–1035 bp). Both the nucleotide and amino acid sequences of the *C. xiaoi gp60* gene showed low identity to those of other *Cryptosporidium* spp. This may explain the inability of the commonly used *gp60* primers to amplify DNA of *C. xiaoi* [23]. Similar to *C. ubiquitum*, *C. canis*, *C. felis*, and *C. ryanae*, the trinucleotide repeats of TCA/TCG/TCT encoding a polyserine tract at the 5 end of the *gp60* gene and widely used to differentiate subtypes within subtype families, were absent in the *gp60* sequence of *C. xiaoi* [12,13,17,24]. However, a polyserine tract encoded by AGC/AGT repeats was observed in the *gp60* gene of the subtype family XXIIIl, and subtypes within XXIIIl differed mostly in the number of AGC/AGT repeats. Similar to most *Cryptosporidium* spp., the GP60 protein of *C. xiaoi* has a classic furin cleavage site "RSRR" between GP40 and GP15, which is absent in *C. ubiquitum*, *C. viatorum*, *Cryptosporidium* chipmunk genotype I and skunk genotype [9,11,12,14].

Based on the sequence analysis, the *gp60* gene of *C. xiaoi* displays an extremely high genetic diversity. The analysis of 298 sequences obtained led to the identification of 94 sequence types in 12 subtype families, including significant length polymorphism and sequence variability. The high sequence heterogeneity in this gene, nevertheless, has made PCR amplification difficult, which together with the large amplicon could

be responsible for the poor amplification efficiency. In addition, some samples (13/355) produced double bands in *gp60* PCR, indicating the presence of concurrent infection with different subtypes in sheep and goats. This may facilitate the occurrence of genetic recombination among *C. xiaoi* subtypes, illustrated by the identification of mosaic sequence patterns and 71 potential recombination events in the overall sequence data. Thus, genetic recombination might be responsible for high sequence heterogeneity in the *gp60* gene of *C. xiaoi*. Genetic recombination at the *gp60* locus was observed in *C. parvum*, *C. hominis*, *C. ubiquitum*, and *C. ryanae* [2,12,17].

The *gp60* subtyping results suggest the presence of host adaptation within *C. xiaoi*. Among the 12 subtype families, XXIIIa, XXIIIc, XXIIIg, and XXIIIj were observed only in goats thus far. For the two breeds of goats, Huanghuai goats in Anhui harboured all subtype families of XXIIIa–XXIIIl. In contrast, all 35 samples from Black goats in Guangdong belonged to XXIIIa. The latter could be due to the reduced genetic diversity of *C. xiaoi* in the province. Previously, host-adapted *gp60* subtype families had been identified in other *Cryptosporidium* spp., such as *C. parvum*, *C. hominis*, *C. felis*, *C. ubiquitum*, *C. tyzzeri*, and *C. ryanae* [2,12,17,25–27].

No obvious correlation was found between the distribution of *C. xiaoi* subtype families and geographic locations in this study. Even though all *C. xiaoi* isolates from three farms in Guangdong belonged to XXIIIa, this subtype family was found in goats on two farms in Anhui. Subtyping data of *C. xiaoi* from more geographic locations and diverse animals are needed for better understanding of the distribution of *C. xiaoi* subtypes. Previously, geographical differences had been reported in the subtype distribution of *C. hominis*, *C. parvum*, *C. felis*, *C. ubiquitum*, *C. ryanae*, and *Cryptosporidium* chipmunk genotype I, indicating possible differences in the transmission of these pathogens [9,12,17,25,27,28].


Preface

The purpose of contraception is to prevent an egg from being fertilized by sperm or to prevent the implantation of a fertilized egg in the uterus. There are many methods of contraception. The ideal method of contraception will prevent pregnancy and protect against sexually transmitted diseases. It is essential to understand and approach each method according to the person's sexual needs. Unfortunately, many people of reproductive age do not have access to contraceptive counseling and services. In developing countries, most pregnancies occur in young and teenage women, unexpectedly and undesirably. Approximately 50% of these pregnancies are artificially terminated under unsafe conditions.

Contraception, especially hormonal contraception, has protective characteristics for those who take it, especially in young adolescence. Contraception was practiced for decades on an empirical basis, but the discovery of the contraceptive pill brought about a real revolution in this field. By using scientific techniques, we managed to prevent ovulation, which is the cornerstone of reproduction. Since the outbreak of AIDS, the usage of birth control pills has decreased because they do not offer any protection against sexually transmitted diseases. On the contrary, barrier contraception that offers protection from STDs prevents direct contact. The contraceptive pill continues to be a unique scientific achievement, which if combined with intrauterine devices creates a protective shield against unwanted pregnancy. The clinical implementation of oral contraception dates back to the 1960s, but its history goes back to the beginning of the 20th century when experimental data showed that the ovaries were organs with hormonal activity. Adolescence is a period in which many physical, emotional, and psychological changes occur in a relatively short time. In this context, one's sexuality, especially in young girls, is developed, with young women particularly vulnerable to possible unwanted pregnancies and STDs. The ever-decreasing age of onset of sexual relations that has been observed worldwide in recent years urges the need for proper sex education and informing teenagers about their contraceptive options. Undoubtedly, accessing information is extremely easy, but there are still many misunderstandings about the methods of contraception today.

The factors that determine whether pregnancy will take place include the fertility of both partners, the year of having intercourse in relation to the time of ovulation, the method of contraception used, and the endogenous efficiency as well as the correct usage of the method. It is impossible to approximate the effectiveness of a contraceptive method isolated from the other factors. Besides effectiveness, contraceptive methods are evaluated by their side effects, ease of implementation, reversibility, and acceptance by the population. The best way to determine the effectiveness of a contraceptive method is by long-term evaluation of a group of sexually active women who use the specific method for a particular period and observing how often pregnancy occurs. The failure rate of each contraceptive method expressed as pregnancies per 100 women per year, is determined by calculating the Pearl Index specific to each method. This involves dividing the number of pregnancies by the total number of months in the observed period for the pairs and then multiplying the resulting quotient by 1200. A method is considered effective when the number of unwanted pregnancies is less than 2 in 100 women who use the method for a year, moderately effective when the rate of unintended pregnancies is up to 10%, and less effective when the rate of unwanted pregnancies is more than 10%. The efficiency of a

method can thus be expressed with two values. The one value results from the set of pairs in which the contraceptive method is used as usual. Therefore, a particular method may be effective for one couple, but not for others. That is, it is a kind of average price effectiveness. The other value refers to the percentage of unwanted pregnancies when the method is used optimally, that is, when used correctly and consistently.

Currently, the World Health Organization (WHO) recommends a 24-month postpartum interval for a subsequent pregnancy. It is estimated that effective family planning globally could prevent 1 in 10 deaths among fetuses by helping women to give birth at least 2 years later because a short period of less than 12 months between pregnancies increases the risk of complications such as low birth weight, premature birth, stillbirth, and neonatal death. Defining contraceptive failure is not easy, as it depends on the population studied. Studies in a young population will suggest a higher failure rate than in an older age group, as fertility is higher in younger people. Consequently, caution is required when interpreting the relevant numbers. "Method failure" includes the inherent risk of failure provided the method is used properly. Percentages are measured in units per 100 women years to the number of women who would become pregnant if 100 of them used this method of contraception for one year. User failure is the failure rate when the method is not used correctly (missed tablets, delayed injections, drug interactions).

With proper guidance from family planning centers, if used consistently and correctly, hormonal contraception (combined hormonal methods, progestogen-only pills, injectables, implants, and intrauterine devices) and non-hormonal methods (copper intrauterine devices [Cu-IUD], sterilization in males and females) are more than 99% effective in preventing pregnancy.

#### **Panagiotis Tsikouras and Nikolaos Nikolettos** Professor, Department of Obstetrics and Gynecology, Democritus University of Thrace, Alexandroupolis, Greece

#### **Werner Rath**

Professor, Gynecology and Obstetrics in the Faculty of Medicine, University of Kiel, Kiel, Germany

#### **Friedrich Von Tempelhoff**

Professor, Gynecology and Obstetrics, St. Vinzenz Teaching Hospital, Hanau, Germany Section 1


Figure 10 shows in the upper view a sequence of colour pictures representing the velocity magnitude, maximized to 1 m/s (red scale ≥ 1 m/s), in a vertical plane bisecting the quadrant and containing the region below the jets of the upper bypass inlet. The pictures are com‐ pletely symmetric since the original data of the quadrant have been mirrored with respect to vertical axis. In this sequence, it is possible to observe many structures forming and moving downwards, towards the lower bypass inlet, in the annular region between the stem and the guide tube. In this view, the black line indicating the level of the stem weld corresponds to

The middle view depicts five time signals of the axial vertical velocity component of the fluid at radially 2 mm from the stem wall. The points are located in plane 7 (blue line in left reference picture) at 5 different azimuthal positions. The signals indicate large vertical intermittent movements downwards, with speeds of the order of 1 m/s and frequencies of 0.1-0.2 Hz which corroborate the impression given by the pictures of the upper view. This is the dynamical mechanism of the mixing responsible for the thermal fatigue of the control rod stems. This ef‐ fect has been further confirmed by simulations of guide tubes without the upper bypass inlet,

The lower view shows the thermal consequences of the above described dynamical process that transports large lumps of warm fluid downwards with relatively large velocities. The maxima of the temperature time signal correlate well with the minima of the axial vertical velocity component. The fact that the temperature signal (in blue) corresponds to only one single fluid point indicates that the lumps of warm fluid cover a large part of the annular gap modelled in the quadrant. This view also shows the temperature signal of two points located inside the solid, namely the first located radially at 0.5 mm from the stem outer wall

reported in Tinoco and Lindqvist (2009), where no such structures are present.

values for the grid at the stem wall in the mixing region

**Figure 10.** Upper view: velocity magnitude limited to 1 m/s (red ≥ 1 m/s). Middle view: time signal of axial vertical velocity component of the fluid in plane 7 (blue line in left reference picture) at 2 mm from the stem wall and for 5 different azimuthal positions. Lower view: temperature signal at three radial points at plane 7 with azimuthal angle of 45º.

However, the central question is still the quality of these simulations. Is a URANS simula‐ tion with good spatial and time resolutions enough to capture both the flow field and the heat transfer correctly? The author is tempted to answer with a "yes" but a more objective answer should be "probably". If the resolutions are adequate, the URANS approach based on SST k-ω model seems to work properly for cases with high enough Reynolds numbers and turbulent flow containing large perturbations. Furthermore, the comparison with ex‐ periments shown in Figure 11 exhibits a rather good agreement for mean temperature and temperature fluctuation distributions along a vertical line 1 mm apart from the stem wall. Incidentally, the material properties in the experiment are those of the prototype. Unfortu‐ nately, no comparisons of the velocity and velocity fluctuation fields were done but it is dif‐ ficult to think that the agreement in the temperature fields shown in Figure 11 may be achieved with a radically different velocity field to that of the experiments.

sults of the structural analyses based on the aforementioned CFD-simulated conditions are consistent with the damage picture obtained by inspection. Using more "conservative" con‐ ditions, e.g. higher heat transfer coefficients, leads to unrealistic short time scales of the

CFD as a Tool for the Analysis of the Mechanical Integrity of Light Water Nuclear Reactors

http://dx.doi.org/10.5772/52691

95

Furthermore, the mathematical and physical consistency of the temperature field inside the stem has been demonstrated by solving of the Inverse Heat Conduction Problem (IHCP), (Taler et al., 2011). The IHCP is defined as the determination of the boundary conditions of the problem from transient temperature histories given at one or more interior locations. The IHCP is a so called ill-posed problem, i.e. any small change on the input data can result in a dramatic change of the solution. By giving CFD-computed time signals of the tempera‐ ture at selected points inside the stem, the temperature signal and the heat flux at the sur‐ face of the stem were recovered with good accuracy. The question that remains is the correctness of the temperature fluctuations at the surface of the stem, i.e. the correctness of the thermal interaction between the solid surface and the near wall region of the fluid. A

Summing up, further structural analyses based on the same CFD-computed conditions have led to a set of measures that have been taken and/or are being implemented. The crud-clean‐ ing flow has been modified to deliver a flow with a temperature of up to 100 ºC instead of the original of 60 ºC. After turning, a control rod stem may acquire surface tensile residual stress which increases the risk of crack initiation. In order to counteract this undesirable ef‐ fect, all control rod stems are now burnished since this procedure creates surface compres‐ sive residual stress that increases the resistance of the stem against damage, i.e. increased protection against crack initiation and crack growth. At locations of the core most exposed to high warm bypass flows, a better material, stainless steel XM-19, has been chosen for the stems of the control rods. Only 50 of the 169 control rods will keep stems of a somewhat poorer material, stainless steel 316L. In the fuel outage of year 2014, all control rods will be tested in order to detect the presence of cracks and, based on the existent experience at that time, a renewed test program will be decided. This set of measures has been conceived as a viable alternative to the very expensive option of eliminating the cause of the mixing prob‐ lem by changing the design of the control rod guide tubes comprising a new location of the

This chapter constitutes a partial view of CFD, both in the sense of limited and favouring, since, for instance, the examples concerning BWR applications are overrepresented and im‐ portant subjects such as nuclear safety and two-phase flows are left aside. As a kind of de‐ fence, it may be argued that the methods used for BWRs are valid, in general, for PWRs and, probably with important modifications, for SuperCritical Water Reactors (SCWRs). As far as CFD in nuclear safety is concerned, the high interest and large amount of work in the subject from, among others, the European Commission, (European Commission, 2005), and the U.S.

definite answer can only be obtained by experimental validation or DNS.

damage.

upper bypass inlet.

**6. Conclusion**

**Figure 11.** Comparison with the steel model experimental data (see Angele et al., 2011); left: mean temperature; right: temperature fluctuations (rms-value).

Then, are the simulated temperature fluctuations inside the solid stem also correct? This question is more difficult to answer since no experimental validation has been carried out but indirect indications about some properties of these fluctuations have nonetheless been obtained. Some of these properties are the order of magnitude of the most energy-contain‐ ing frequencies of the temperature fluctuations at stem wall and of the associated heat transfer coefficients. Structural analyses (see e.g. Forsmarks Kraftgrupp, 2009) using this range of frequencies, together with the large temperature amplitudes and velocities of the order of 1 m/s, show that this kind of heat transfer is associated with the initiation of cracks on the stem surface. Moreover, the analyses also show that the time scale of the crack de‐ velopment that resulted in broken control rod stems is consistent both with the geometry of the stem (hollow welded joining; see Tinoco and Lindqvist, 2009) and the thermal loadings arising from the heat transfer process described by the CFD simulations. In general, the re‐ sults of the structural analyses based on the aforementioned CFD-simulated conditions are consistent with the damage picture obtained by inspection. Using more "conservative" con‐ ditions, e.g. higher heat transfer coefficients, leads to unrealistic short time scales of the damage.

Furthermore, the mathematical and physical consistency of the temperature field inside the stem has been demonstrated by solving of the Inverse Heat Conduction Problem (IHCP), (Taler et al., 2011). The IHCP is defined as the determination of the boundary conditions of the problem from transient temperature histories given at one or more interior locations. The IHCP is a so called ill-posed problem, i.e. any small change on the input data can result in a dramatic change of the solution. By giving CFD-computed time signals of the tempera‐ ture at selected points inside the stem, the temperature signal and the heat flux at the sur‐ face of the stem were recovered with good accuracy. The question that remains is the correctness of the temperature fluctuations at the surface of the stem, i.e. the correctness of the thermal interaction between the solid surface and the near wall region of the fluid. A definite answer can only be obtained by experimental validation or DNS.

Summing up, further structural analyses based on the same CFD-computed conditions have led to a set of measures that have been taken and/or are being implemented. The crud-clean‐ ing flow has been modified to deliver a flow with a temperature of up to 100 ºC instead of the original of 60 ºC. After turning, a control rod stem may acquire surface tensile residual stress which increases the risk of crack initiation. In order to counteract this undesirable ef‐ fect, all control rod stems are now burnished since this procedure creates surface compres‐ sive residual stress that increases the resistance of the stem against damage, i.e. increased protection against crack initiation and crack growth. At locations of the core most exposed to high warm bypass flows, a better material, stainless steel XM-19, has been chosen for the stems of the control rods. Only 50 of the 169 control rods will keep stems of a somewhat poorer material, stainless steel 316L. In the fuel outage of year 2014, all control rods will be tested in order to detect the presence of cracks and, based on the existent experience at that time, a renewed test program will be decided. This set of measures has been conceived as a viable alternative to the very expensive option of eliminating the cause of the mixing prob‐ lem by changing the design of the control rod guide tubes comprising a new location of the upper bypass inlet.

## **6. Conclusion**

However, the central question is still the quality of these simulations. Is a URANS simula‐ tion with good spatial and time resolutions enough to capture both the flow field and the heat transfer correctly? The author is tempted to answer with a "yes" but a more objective answer should be "probably". If the resolutions are adequate, the URANS approach based on SST k-ω model seems to work properly for cases with high enough Reynolds numbers and turbulent flow containing large perturbations. Furthermore, the comparison with ex‐ periments shown in Figure 11 exhibits a rather good agreement for mean temperature and temperature fluctuation distributions along a vertical line 1 mm apart from the stem wall. Incidentally, the material properties in the experiment are those of the prototype. Unfortu‐ nately, no comparisons of the velocity and velocity fluctuation fields were done but it is dif‐ ficult to think that the agreement in the temperature fields shown in Figure 11 may be

**Figure 11.** Comparison with the steel model experimental data (see Angele et al., 2011); left: mean temperature;

Then, are the simulated temperature fluctuations inside the solid stem also correct? This question is more difficult to answer since no experimental validation has been carried out but indirect indications about some properties of these fluctuations have nonetheless been obtained. Some of these properties are the order of magnitude of the most energy-contain‐ ing frequencies of the temperature fluctuations at stem wall and of the associated heat transfer coefficients. Structural analyses (see e.g. Forsmarks Kraftgrupp, 2009) using this range of frequencies, together with the large temperature amplitudes and velocities of the order of 1 m/s, show that this kind of heat transfer is associated with the initiation of cracks on the stem surface. Moreover, the analyses also show that the time scale of the crack de‐ velopment that resulted in broken control rod stems is consistent both with the geometry of the stem (hollow welded joining; see Tinoco and Lindqvist, 2009) and the thermal loadings arising from the heat transfer process described by the CFD simulations. In general, the re‐

right: temperature fluctuations (rms-value).

94 Nuclear Reactor Thermal Hydraulics and Other Applications

achieved with a radically different velocity field to that of the experiments.

This chapter constitutes a partial view of CFD, both in the sense of limited and favouring, since, for instance, the examples concerning BWR applications are overrepresented and im‐ portant subjects such as nuclear safety and two-phase flows are left aside. As a kind of de‐ fence, it may be argued that the methods used for BWRs are valid, in general, for PWRs and, probably with important modifications, for SuperCritical Water Reactors (SCWRs). As far as CFD in nuclear safety is concerned, the high interest and large amount of work in the subject from, among others, the European Commission, (European Commission, 2005), and the U.S. Department of Energy, Idaho National Laboratory, (Johnson et al., 2006), make and analysis and a review of the subject rather superfluous.

spirit of Speziale, (Speziale, 1998), an approach which has been further commented by Tino‐

CFD as a Tool for the Analysis of the Mechanical Integrity of Light Water Nuclear Reactors

http://dx.doi.org/10.5772/52691

97

Even if LES may be considered in many cases still too resource demanding, it is undeniably the approach of the near future provided that the computer development trend is main‐ tained. However, conjugate heat transfer simulations of industrial applications, i.e. simula‐ tions at high Reynolds numbers, involved geometries and complex boundary conditions, appear to lack guidelines for ensuring acceptable quality with a suitable uncertainty. LES, as one of the simulation alternatives for these applications, seems to have taken a first step to‐ wards the definition of more complete rules for conjugate heat transfer simulations with the work of Carlsson and Veber (2010). Using a DNS data base for channel flow, (The University of Tokyo, 2012), mesh requirements for LES simulations of heat transfer are established, as functions of the Reynolds and Prandtl numbers. This work should be extended to conjugate heat transfer and temperature fluctuations in the solid by using the results of Tiselj et al.

To conclude, this study has tried to show that the analysis of the mechanical integrity of light water reactors as a rather complex task, multidisciplinary and in continuous progress, evolving towards improved safety due to Regulatory demands, new and more advanced methods of analysis and taking advantage of the stably increasing available computer pow‐ er. Additionally, this work has tried to describe, although incompletely and briefly, the his‐ torical progress of the currently accepted methodology and future prospects. Other types of analysis included in the existing methodology, which are not mentioned here due to space limitations, are, for example, studies of thermal loads in transients such as the loss of offsite power (Tinoco et al., 2005) or estimating the moderator tank maximum temperature due to

As it might have become apparent from this study, the FEM method for the analysis of structures is considered well established and sufficiently accurate, giving results that do not need verification or experimental validation. The case of three-dimensional numerical com‐ putations (CFD) applied to the thermal-hydraulics is very different, mainly due to turbu‐ lence, which still lacks an explanatory theory, and to the presence of two-phase flows where the knowledge about the physical processes involved is far from complete. Therefore, the re‐ sults obtained using three-dimensional numerical computations require validation or at least verification, which is not always possible for complex systems such as nuclear reactors,

(2001), Tiselj et al. (2004), Tiselj (2011) and Tiselj and Cizelj (2012).

gamma radiation and subcooled boiling heat transfer (Tinoco et al., 2008).

an issue that has been discussed by Tinoco et al. (2010c).

**Author details**

Hernan Tinoco1,2

1 Forsmarks Kraftgrupp AB, Sweden

2 Onsala Ingenjörsbyrå AB, Sweden

co et al. (2010c).

As pointed out by Tinoco et al. (2010c), two-phase flow simulations still have a relatively high degree of uncertainty and they have not reached the level of quality of single-phase simulations. The physics involved in two-phase phenomena is still not well understood, due mainly to the measuring difficulties entailed by the requirement of local knowledge of the processes needed in CFD. Consequently, the models available lack the distinctive prediction capability of CFD because they are usually based on information collected as relatively gen‐ eral correlations. A fundamental example is the experimental lack of knowledge about the modification by boiling of the detailed structure of a boundary layer at a wall. This deficien‐ cy leads to wrong predictions of flow resistance and void distribution in, for instance, pipe flow with boiling from the walls.

Another topic that has not been mentioned in this work is the field of acoustic perturbations in the reactor system, especially in the parts corresponding to pipe networks. The problem of flow-induced structural resonances has become more topical due to the increased interest in operating the reactors at uprated power output. The new components and/or the in‐ creased flow rates necessary for achieving the upgrade may lead to the generation of pres‐ sure waves that may excite structural vibration modes and increase the risk of mechanical fatigue. CFD may be used to analyse the pipe-network system if the geometry is realistically represented, the grid has a suitable resolution, the turbulence model is appropriate and, in the case of steam, compressibility is included (Lirvat et al., 2012). Post-processing of the gen‐ erated data can provide information about the flow induced excitation modes, the source of the excitation frequencies/modes and possible standing pressure waves. In the past, at‐ tempts have been carried out to collect acoustic signals generated in complex systems like a nuclear reactor in order to detect possible deviations from normal operation of the different components. Any success has failed to turn up not due to the process of acquiring the data, which is relatively easy, but to the difficulties in interpreting the signal constituted by the superposition of broadcasted pressure waves from every component that may act as a source. In the future, CFD might help identifying the sources and describing how the differ‐ ent pressure waves propagate in the system. Perhaps, detecting the leakage of valves in complex systems like a nuclear reactor by means of acoustic signals may become possible.

As usual when trying to solve a problem, more questions than those initially asked arise during the solution process. The case of the control rod cracks in no exception and, as men‐ tioned before, the apparent success of the URANS simulations with the SST k-ω model rais‐ es several questions, namely if this is the merit of the model, and at which Reynolds numbers the URANS approach begins to work, if the associate heat transfer, including tem‐ perature fluctuations, is correct, and with which resolutions in time and space, etc. All these questions should be investigated in the future since URANS may constitute a realistic alter‐ native, especially at high Reynolds number, to the promising LES approach that still is too expensive for relatively large applications. Another alternative that has already been used with encouraging results, (Lindqvist, 2011), is Very Large Eddy Simulation (VLES) in the spirit of Speziale, (Speziale, 1998), an approach which has been further commented by Tino‐ co et al. (2010c).

Even if LES may be considered in many cases still too resource demanding, it is undeniably the approach of the near future provided that the computer development trend is main‐ tained. However, conjugate heat transfer simulations of industrial applications, i.e. simula‐ tions at high Reynolds numbers, involved geometries and complex boundary conditions, appear to lack guidelines for ensuring acceptable quality with a suitable uncertainty. LES, as one of the simulation alternatives for these applications, seems to have taken a first step to‐ wards the definition of more complete rules for conjugate heat transfer simulations with the work of Carlsson and Veber (2010). Using a DNS data base for channel flow, (The University of Tokyo, 2012), mesh requirements for LES simulations of heat transfer are established, as functions of the Reynolds and Prandtl numbers. This work should be extended to conjugate heat transfer and temperature fluctuations in the solid by using the results of Tiselj et al. (2001), Tiselj et al. (2004), Tiselj (2011) and Tiselj and Cizelj (2012).

To conclude, this study has tried to show that the analysis of the mechanical integrity of light water reactors as a rather complex task, multidisciplinary and in continuous progress, evolving towards improved safety due to Regulatory demands, new and more advanced methods of analysis and taking advantage of the stably increasing available computer pow‐ er. Additionally, this work has tried to describe, although incompletely and briefly, the his‐ torical progress of the currently accepted methodology and future prospects. Other types of analysis included in the existing methodology, which are not mentioned here due to space limitations, are, for example, studies of thermal loads in transients such as the loss of offsite power (Tinoco et al., 2005) or estimating the moderator tank maximum temperature due to gamma radiation and subcooled boiling heat transfer (Tinoco et al., 2008).

As it might have become apparent from this study, the FEM method for the analysis of structures is considered well established and sufficiently accurate, giving results that do not need verification or experimental validation. The case of three-dimensional numerical com‐ putations (CFD) applied to the thermal-hydraulics is very different, mainly due to turbu‐ lence, which still lacks an explanatory theory, and to the presence of two-phase flows where the knowledge about the physical processes involved is far from complete. Therefore, the re‐ sults obtained using three-dimensional numerical computations require validation or at least verification, which is not always possible for complex systems such as nuclear reactors, an issue that has been discussed by Tinoco et al. (2010c).

## **Author details**

Department of Energy, Idaho National Laboratory, (Johnson et al., 2006), make and analysis

As pointed out by Tinoco et al. (2010c), two-phase flow simulations still have a relatively high degree of uncertainty and they have not reached the level of quality of single-phase simulations. The physics involved in two-phase phenomena is still not well understood, due mainly to the measuring difficulties entailed by the requirement of local knowledge of the processes needed in CFD. Consequently, the models available lack the distinctive prediction capability of CFD because they are usually based on information collected as relatively gen‐ eral correlations. A fundamental example is the experimental lack of knowledge about the modification by boiling of the detailed structure of a boundary layer at a wall. This deficien‐ cy leads to wrong predictions of flow resistance and void distribution in, for instance, pipe

Another topic that has not been mentioned in this work is the field of acoustic perturbations in the reactor system, especially in the parts corresponding to pipe networks. The problem of flow-induced structural resonances has become more topical due to the increased interest in operating the reactors at uprated power output. The new components and/or the in‐ creased flow rates necessary for achieving the upgrade may lead to the generation of pres‐ sure waves that may excite structural vibration modes and increase the risk of mechanical fatigue. CFD may be used to analyse the pipe-network system if the geometry is realistically represented, the grid has a suitable resolution, the turbulence model is appropriate and, in the case of steam, compressibility is included (Lirvat et al., 2012). Post-processing of the gen‐ erated data can provide information about the flow induced excitation modes, the source of the excitation frequencies/modes and possible standing pressure waves. In the past, at‐ tempts have been carried out to collect acoustic signals generated in complex systems like a nuclear reactor in order to detect possible deviations from normal operation of the different components. Any success has failed to turn up not due to the process of acquiring the data, which is relatively easy, but to the difficulties in interpreting the signal constituted by the superposition of broadcasted pressure waves from every component that may act as a source. In the future, CFD might help identifying the sources and describing how the differ‐ ent pressure waves propagate in the system. Perhaps, detecting the leakage of valves in complex systems like a nuclear reactor by means of acoustic signals may become possible.

As usual when trying to solve a problem, more questions than those initially asked arise during the solution process. The case of the control rod cracks in no exception and, as men‐ tioned before, the apparent success of the URANS simulations with the SST k-ω model rais‐ es several questions, namely if this is the merit of the model, and at which Reynolds numbers the URANS approach begins to work, if the associate heat transfer, including tem‐ perature fluctuations, is correct, and with which resolutions in time and space, etc. All these questions should be investigated in the future since URANS may constitute a realistic alter‐ native, especially at high Reynolds number, to the promising LES approach that still is too expensive for relatively large applications. Another alternative that has already been used with encouraging results, (Lindqvist, 2011), is Very Large Eddy Simulation (VLES) in the

and a review of the subject rather superfluous.

96 Nuclear Reactor Thermal Hydraulics and Other Applications

flow with boiling from the walls.

Hernan Tinoco1,2

1 Forsmarks Kraftgrupp AB, Sweden

2 Onsala Ingenjörsbyrå AB, Sweden

## **References**

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**Section 2**

**General Thermal Hydraulic Applications**

**General Thermal Hydraulic Applications**

**Chapter 4**

**Thermal Hydraulics Design and**

**Analysis Methodology for a Solid-Core**

Ten-See Wang, Francisco Canabal, Yen-Sen Chen,

Additional information is available at the end of the chapter

Gary Cheng and Yasushi Ito

http://dx.doi.org/10.5772/52569

**1. Introduction**

in the Rover/NREVA era.

**Nuclear Thermal Rocket Engine Thrust Chamber**

Nuclear thermal propulsion [1] can carry far larger payloads and reduce travel time for astro‐ nauts going to Mars than is now possible with chemical propulsion. The most feasible con‐ cept, extensively tested during the Rover/NERVA (Nuclear Engine for Rocket Vehicle Application) era, is the solid-core concept [2]. It features a solid-core nuclear reactor consist‐ ing of hundreds of heat generating prismatic flow elements. Each flow element contains tens of tubular flow channels through which the working fluid, hydrogen, acquires energy and ex‐ pands in a high expansion nozzle to generate thrust. Approximately twenty nuclear thermal engines with different sizes and designs were tested during that era. Using hydrogen as pro‐ pellant, a solid-core design typically delivers specific impulses (ISP) on the order of 850 to 1000 s, about twice that of a chemical rocket such as the Space Shuttle Main Engine (SSME).

With the announcement of the Vision for Space Exploration on January 14, 2004, NASA Marshall Space Flight Center started a two-year solid-core nuclear rocket development ef‐ fort in 2006. The tasks included, but not limited to, nuclear systems development, design methodology development, and materials development. In 2011, with the retirement of Space Shuttle fleets, and NASA's shifting focus to further out places such as Mars and aste‐ roids, nuclear thermal propulsion is likely to garner substantial interest again. It is therefore timely to discuss the design methodology development effort from 2006 to 2007, entitled "Multiphysics Thrust Chamber Modeling", which developed an advanced thermal hydraul‐ ics computational methodology and studied a solid-core, nuclear thermal engine designed

> © 2013 Wang et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 Wang et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and reproduction in any medium, provided the original work is properly cited.


A collection of wild quinoas in Carchi and Chimborazo showed a significant difference in seed morphology (unpublished data). The seed gathered from farmers' fields in Carchi showed a pitted surface (Figure 3A). It is likely that these plants are *C. berlandieri*, *C. hircinum*, or the *C. quinoa* ssp. *milleanum* [57]. On the other hand, the seed collected in Chimborazo had a smooth surface (Figure 3B). It is possible that this species belongs to the *C. album* complex, which has a cosmopolitan distribution around the world [58]. Molecular studies are necessary to confirm this hypothesis. *Plants* **2021**, *10*, x 13 of 23

**Figure 3.** Wild quinoa relatives' seed surfaces. (**A**) Probably *C. quinoa* ssp. *milleanum,* or *C. berlandieri*, or *C. hircinium*, with a pitted surface. (**B**) Probably *C. album*, with a smooth surface. Magnitude: 60×. Photos: L. Hinojosa. **Figure 3.** Wild quinoa relatives' seed surfaces. (**A**) Probably *C. quinoa* ssp. *milleanum,* or *C. berlandieri*, or *C. hircinium*, with a pitted surface. (**B**) Probably *C. album*, with a smooth surface. Magnitude: 60×. Photos: L. Hinojosa.

Interspecific hybridizations in nature between *C. quinoa* and *C. berlandierie, C. hircinum,* and *C quinoa* ssp. *milleanum* have been reported [54,55,59]. Plant breeders have intentionally created interspecific crosses (simple and reciprocal) in order to recombine favorable traits (e.g., heat tolerance) present in different species and to concentrate them in the selected offspring [60]. Studies are required to identify if wild quinoas in Ecuador can cross with cultivated quinoas; this feature could be beneficial to breeding programs. Interspecific hybridizations in nature between *C. quinoa* and *C. berlandierie, C. hircinum,* and *C quinoa* ssp. *milleanum* have been reported [54,55,59]. Plant breeders have intentionally created interspecific crosses (simple and reciprocal) in order to recombine favorable traits (e.g., heat tolerance) present in different species and to concentrate them in the selected offspring [60]. Studies are required to identify if wild quinoas in Ecuador can cross with cultivated quinoas; this feature could be beneficial to breeding programs.

quinoa to coastal or tropical areas in Ecuador. In 2014, Peralta et al. evaluated the adaptability of 269 quinoa accessions from the quinoa germplasm existing at INIAP, under the agro-ecological conditions of the Santa Elena Peninsula; however, all accessions evaluated proved to be poorly adapted to the area mainly due to high temperature [62]. The interest in producing quinoa on the coast of Ecuador arises from the increase in consumption worldwide, high international prices [63], and the experiences of coastal production in Chile [64] and Peru [65]. In addition, knowing quinoa's great capacity for adaptation [3] makes the northern area of the province of Los Rios (Quevedo) a suitable niche for the

In collaboration with other researchers, multiple trials were established in 2017 to evaluate quinoa genotypes from the coast and south of Chile, Argentina, and Ecuador. In the first trial, 21 accessions were sourced from Chile and Argentina, and grown from August to December 2017 at the research station "La Maria" of the State Technical University of Quevedo located in Mocache, Quevedo [66]. The results demonstrated the feasibility of quinoa production in this area. Days to maturity ranged from 90 to 143 days after sowing and yield ranged from 346 to 470 g m−2. Several colors in the grain such as yellow, white,

In the second trial at Mocache, Quevedo, genotypes from Ecuador, Chile and Argentina were surface-seeded and grown from June to September 2019 [67]. Although this trial was affected by poor germination, the genotype O-10 (red leaf color) performed well, with a crop cycle of 110 days, a grain yield of 3723 kg ha−1, a harvest index of 0.41, and plant

**5. Quinoa Adaptation to Tropical Areas**

production of rainfed quinoa (Figure 4).

red, and black were described.

height of 90 cm.

#### **5. Quinoa Adaptation to Tropical Areas**

Of the five quinoa ecotypes described above, the valley ecotype is predominantly produced and consumed in Ecuador [61]. Little information exists on the adaptation of quinoa to coastal or tropical areas in Ecuador. In 2014, Peralta et al. evaluated the adaptability of 269 quinoa accessions from the quinoa germplasm existing at INIAP, under the agro-ecological conditions of the Santa Elena Peninsula; however, all accessions evaluated proved to be poorly adapted to the area mainly due to high temperature [62]. The interest in producing quinoa on the coast of Ecuador arises from the increase in consumption worldwide, high international prices [63], and the experiences of coastal production in Chile [64] and Peru [65]. In addition, knowing quinoa's great capacity for adaptation [3] makes the northern area of the province of Los Rios (Quevedo) a suitable niche for the production of rainfed quinoa (Figure 4). *Plants* **2021**, *10*, x 14 of 23

**Figure 4.** Average monthly precipitation and temperature for the last ten years (2010–2019) in the Quevedo area. **Figure 4.** Average monthly precipitation and temperature for the last ten years (2010–2019) in the Quevedo area.

Follow-up investigations were carried out (data not yet published), which demonstrate that the best genotype (O-10) under these conditions, needs 1300 accumulated degree days to finish its cultivation cycle in 110 days. In addition, based on the efficient use of nitrogen in rainfed conditions, it is recommended to apply 62 kg N ha−1 if the objective is to achieve maximum N use efficiency. However, if the objective is to achieve maximum grain performance, it is recommended to apply 110 kg N ha−1 to achieve a grain yield of 4700 kg ha−1. This research also showed that an increase in the nitrogen rate from 0 to 200 kg ha−1 results in an increase in protein in the grain from 13% to 17%. In collaboration with other researchers, multiple trials were established in 2017 to evaluate quinoa genotypes from the coast and south of Chile, Argentina, and Ecuador. In the first trial, 21 accessions were sourced from Chile and Argentina, and grown from August to December 2017 at the research station "La Maria" of the State Technical University of Quevedo located in Mocache, Quevedo [66]. The results demonstrated the feasibility of quinoa production in this area. Days to maturity ranged from 90 to 143 days after sowing and yield ranged from 346 to 470 g m−2 . Several colors in the grain such as yellow, white, red, and black were described.

Currently, at the State Technical University of Quevedo (Universidad Técnica Estatal de Quevedo), research continues on adapting the red O-5 genotype and performing hybridizations with the cream-white O-3 genotype to obtain quinoa populations with adaptation criteria of the O-3, but with certain characteristics of O-5. Finally, it should be noted that our small collection of quinoas has shown the feasibility of being able to carry out In the second trial at Mocache, Quevedo, genotypes from Ecuador, Chile and Argentina were surface-seeded and grown from June to September 2019 [67]. Although this trial was affected by poor germination, the genotype O-10 (red leaf color) performed well, with a crop cycle of 110 days, a grain yield of 3723 kg ha−1 , a harvest index of 0.41, and plant height of 90 cm.

two cultivation cycles a year, the first cycle from May to August and the second cycle from September to December. January to April is reserved for maize production because none of our quinoa genotypes will tolerate the excessive humidity that is generated during the first months of the year (Figure 4). **6. Quinoa Processing and Agroindustry**  Quinoa was widely used in South America during pre-Hispanic times; however, after the Spanish conquest, its cultivation and consumption were reduced to small areas Follow-up investigations were carried out (data not yet published), which demonstrate that the best genotype (O-10) under these conditions, needs 1300 accumulated degree days to finish its cultivation cycle in 110 days. In addition, based on the efficient use of nitrogen in rainfed conditions, it is recommended to apply 62 kg N ha−1 if the objective is to achieve maximum N use efficiency. However, if the objective is to achieve maximum grain performance, it is recommended to apply 110 kg N ha−1 to achieve a grain yield of 4700 kg ha−1 . This research also showed that an increase in the nitrogen rate from 0 to 200 kg ha−1 results in an increase in protein in the grain from 13% to 17%.

scattered in mountainous areas of the Andes [32]. Since then, the grain was scarcely known or commercialized; however, the "re-discovery" of quinoa resulted in an explosion of its consumption, especially in Europe and the United States, in recent decades. This

which have a moderate protein content (>15%), a good balance of all essential amino acids, dietary fiber, lipids, carbohydrates, vitamins, and minerals, and low glycemic index when consumed [13,68]. Functional compounds in quinoa such as polyphenols, phytosterols, and flavonoids have also been found to have important nutraceutical benefits [13,69].

The Ecuadorian agroindustry processes innovative quinoa products for culinary, pharmaceutical, and cosmetic uses. Farmers and agribusiness enterprises that consider only grain production without the application of transformation technologies downgrade the commercial value of quinoa [21]. Several public and private institutions, universities,

*Quinoa Transformation*

Currently, at the State Technical University of Quevedo (Universidad Técnica Estatal de Quevedo), research continues on adapting the red O-5 genotype and performing hybridizations with the cream-white O-3 genotype to obtain quinoa populations with adaptation criteria of the O-3, but with certain characteristics of O-5. Finally, it should be noted that our small collection of quinoas has shown the feasibility of being able to carry out two cultivation cycles a year, the first cycle from May to August and the second cycle from September to December. January to April is reserved for maize production because none of our quinoa genotypes will tolerate the excessive humidity that is generated during the first months of the year (Figure 4).

#### **6. Quinoa Processing and Agroindustry**

Quinoa was widely used in South America during pre-Hispanic times; however, after the Spanish conquest, its cultivation and consumption were reduced to small areas scattered in mountainous areas of the Andes [32]. Since then, the grain was scarcely known or commercialized; however, the "re-discovery" of quinoa resulted in an explosion of its consumption, especially in Europe and the United States, in recent decades. This growth is largely a result of the high nutritional value of its gluten-free seeds and leaves, which have a moderate protein content (>15%), a good balance of all essential amino acids, dietary fiber, lipids, carbohydrates, vitamins, and minerals, and low glycemic index when consumed [13,68]. Functional compounds in quinoa such as polyphenols, phytosterols, and flavonoids have also been found to have important nutraceutical benefits [13,69].

#### *Quinoa Transformation*

The Ecuadorian agroindustry processes innovative quinoa products for culinary, pharmaceutical, and cosmetic uses. Farmers and agribusiness enterprises that consider only grain production without the application of transformation technologies downgrade the commercial value of quinoa [21]. Several public and private institutions, universities, and research centers in Ecuador are currently developing improved varieties, including thoroughly characterizing the physico-chemical and nutritional traits, protein and amino acid contents, fatty acids, vitamins and minerals, phytohormones, antioxidants, phytosterols, and dietary fiber, as well as the identification and use of saponins [70–73]. Additionally, applications of thermal processes and bioprocesses have been studied in order to increase mineral bioavailability, the level of acceptability, and the nutraceutical value of quinoa grain [74].

The range of quinoa products that are produced and marketed in Ecuador include: whole grain, quinoa flour, quinoa flour mixtures with oats or amaranth, baby food porridge, granola, energy bars, soft drinks, quinoa expanded as breakfast cereal, biscuits, alfajores (a traditional dessert), and quinoa bread with substitution percentages reaching 30% [61,75]. On a smaller scale, and only in warehouses of products produced by farmers (fair trade), noodles are sold with some percentages of substitution. The Food World Programme (WFP), PANN-2000 (Programa de Alimentos), and "Aliméntate Ecuador" ("Feed Ecuador") established as a mandate that both porridge and drinks for children must include quinoa as a raw material in their formulas [21]. Currently, solid fermentation processes are being tested to obtain vegetable meat and technologies are being optimized to produce milk- and yogurt-type drinks, products desired by children, adolescents, and adults, with national and international market potential among subjects with gluten allergy problems [75]. Additionally, precooked quinoa facilitates quinoa preparation and consumption in schools and assistance centers. The product can be seasoned with vegetables and can be introduced without much difficulty in various markets in Europe and the United States.

Quinoa leaves can be used as a nutritious vegetable, as they contain carotenoids, iron, and other micronutrients. The phytochemical profile shows that the leaves (60–80 days of cultivation) have low saponin contents. Their nutritional profile surpasses the grain, and they possess interesting potential in nutrition and food. Quinoa leaves can be used in the preparation of salads, soups, main dishes, and as raw material to enter the food industry, which wants to offer a continuous movement of new products in order to remain in the market, thereby contributing to the change of the production matrix [76,77].

It is worth highlighting the collaborations that private industry establishes with farmers capable of supplying large volumes of grain. Manufacturers in the food sector establish contracts with farmers. Contract farming is opening a very interesting way to consolidate the sustainability of the value chain [21]. Producers in the province of Chimborazo focus their attention on the production of organic fair-trade quinoa for traditional food applications in those areas less appropriate for intensification. However, Ecuadorian farmers face competition from other countries, as new varieties and models pave the way for large-scale production under different conditions.

#### **7. Participatory Plant Breeding Project between WSU and APROSANAMY (Case Study)**

The Association of Producers of Seeds and Nutritious Andean Foods Mushuk Yuyay (APROSANAMY) was formed in 1994, with the main objective to focus on seed production of Andean crops such as barley, quinoa, faba bean, amaranth, and peas. In 2004, APROSANAMY started to add value to their production—for example, in the processing of barley and quinoa flour. In 2018, a new processing and storage facility was built to allow for the expansion of production. Currently, APROSANAMY has 69 producers from 18 communities from the cantons Cañar, Suscal, and El Tambo in Cañar province [78]. The province of Cañar, with a population of 281,396 inhabitants, is located between the provinces of Chimborazo and Azuay, in southcentral Ecuador [29].

Quinoa researchers at Washington State University (WSU) were first connected with APROSANAMY through Alan Adams, a former Peace Corps volunteer who worked in Quilloac, Cañar province, from 1967 to 1969. In May 2013, Alan received an email message from Nicolas Pichazaca requesting that he join in the work of APROSANAMY. Alan began researching, writing grants, and reaching out to potential collaborators. Based on a short article on quinoa in National Geographic that his wife Paulette read about WSU quinoa research, Alan contacted researcher Kevin Murphy and his Ecuadorian PhD student, Leonardo Hinojosa [79]. This began a formal arrangement between APROSANAMY and WSU to collaborate on quinoa and barley research. After initial discussions between Murphy and Hinojosa of WSU and Nicolas Pichazaca, Jose Luis Pichazaca, and Antonio Guaman of APROSANAMY regarding collaboration strategies with quinoa breeding, a two-pronged approach was implanted, including (a) evolutionary participatory breeding (EPB), and (b) evaluations of homogeneous cultivars and advanced breeding lines.

The first strategy (EPB) included sharing a diverse breeding population to stimulate a participatory selection approach [80]. This approach involved selection from diverse bi-parental populations by APROSANAMY farmers and researchers, as well as natural selection in the different environments of Cañar, utilizing an evolutionary participatory breeding (EPB) approach [81,82]. EPB combines evolutionary breeding through natural selection with participatory selection by farmers and breeders to develop populations adapted to locally prevalent diseases and abiotic pressures [83,84]. These populations retain a significant amount of genetic variation, allowing the population to rapidly evolve in response to climate change and the resulting unpredictable fluctuations in environmental conditions [85,86]. Recent shifts in rainfall patterns and climate instability are key concerns voiced by Kichwa Kañari farmers.

Population development proceeded in two distinct phases. Phase I of the EPB approach focused on population development that incorporated traits of importance to Kichwa Kañari farmers. Based on multiple discussions between WSU and APROSANAMY, traits such as (a) early maturity to mitigate problems with preharvest sprouting due to increasingly unpredictable late season rains, (b) large seed size, (c) seed yield, and (d) red leaf color emerged as particularly important. Leonardo Hinojosa crossed cultivars such as "Titicaca" and "Puno", and the red-leafed breeding line "3964" (developed collaboratively by researchers at Brigham Young University and WSU) with more regionally adapted varieties such as "Pasankalla", a cultivar widely grown in Peru, and "CICA", an Altiplano

cultivar from Peru that was shared kindly by Juan Antonio Gonzales from Argentina. Additionally, the "Titicaca", "Puno", "3964", "QQ74", "Colorado 407D", "Cahuil", and "Kaslaea" varieties were grown as control cultivars next to the populations (Table 6).

**Table 6.** Phase I and Phase II WSU evolutionary participatory breeding (EPB) populations grown by APROSANAMY in Cañar province, Ecuador.

These Phase I populations were planted by an APROSANAMY-WSU team in 2016 (Figure 5C) and have been replanted each year since then. By March 2018, Nicolas Pichazaca had selected the "Puno/Pasankalla" population and the "Kaslaea", "QQ74", "Colorado 407D", and "3964" cultivars (Figure 5D), which were the most promising genotypes mainly due to early maturity, large seed size, and leaf color. These will continue to be grown in the future.

Phase II crosses continued to introduce new genetic variations designed to introgress traits such as heat tolerance ("Pison" and "QQ74") [8], early maturity (Japanese Strain, "Titicaca") red leaf color ("3964" and "MisaMisa"), and seed yield ("Titicaca", "Kaslaea") into adapted varieties such as "MisaMisa", "Pasankalla", and "INIAP Tunkahuan" (Figure 5E–G and Table 6).

The second strategy focused on testing pureline varieties and breeding lines. Fifty lines from the F6 population ("Cahuil"/"PI 510534"), created by former WSU graduate student Adam Peterson, were planted in Cañar in February 2019. The parents from this population include "Cahuil", a variety that originated from Chile with good adaptation to Washington State, and "PI 510534", an accession from National Plant Germplasm System of USDA that originated from the valley of Peru. Unfortunately, the seed germination from the lines was very low and drought and frost conditions caused the loss of the trial; however, new plantings are planned in the future with the same lines.

In October 2019, Kevin Murphy, Nicolas Pichazaca, Cristina Ocaña Gallegos (a new graduate student at WSU) planted 37 quinoa lines from the previous year's selections. The trial was affected by high pressure of downy mildew and lines derived from "Puno"/"Pasankalla" showed high resistance to this pathogen.

In Table 7, we detail the timeline of the collaboration between APROSANAMY and WSU from 2015 to 2020. It is necessary to emphasize that in addition to the work on quinoa, WSU and APROSANAMY have been working in parallel with barley—including malting barley and hulless food barley. Currently, there are five promising lines under evaluation. Lines 13WA146-7, 13WA-146.3, and 13WA-146.1 were selected for their elongated grain shapes suitable for barley flour, "machika", and pleasant smells during the manufacturinggrinding process; lines 13WA-146-10 and 13WA-126.6 were selected for "Arroz de Cebada" ("Barley Rice"), a traditional dish in the Ecuadorian highlands.

**Figure 5.** Asociación de Productores de Semillas y Alimentos Nutricionales Andinos Mushuk Yuyay (APROSANAMY) and Washington State University (WSU) activities. (**A**) Kañari planting ceremony; **(B)** field preparation, plowing (Macy Hagler, WSU student); (**C**) planting quinoa and barley with WSU students; (**D**) Line 3964 (red) and Colorado 407D (yellow); (**E**–**G**) introduction of new genetic variation (red color leaves). Photos by: L. Hinojosa, N. Pichazaca, and J. Kellogg. **Figure 5.** Asociación de Productores de Semillas y Alimentos Nutricionales Andinos Mushuk Yuyay (APROSANAMY) and Washington State University (WSU) activities. (**A**) Kañari planting ceremony; **(B)** field preparation, plowing (Macy Hagler, WSU student); (**C**) planting quinoa and barley with WSU students; (**D**) Line 3964 (red) and Colorado 407D (yellow); (**E**–**G**) introduction of new genetic variation (red color leaves). Photos by: L. Hinojosa, N. Pichazaca, and J. Kellogg.

The second strategy focused on testing pureline varieties and breeding lines. Fifty lines from the F6 population ("Cahuil"/"PI 510534"), created by former WSU graduate student Adam Peterson, were planted in Cañar in February 2019. The parents from this population include "Cahuil", a variety that originated from Chile with good adaptation to Washington State, and "PI 510534", an accession from National Plant Germplasm System of USDA that originated from the valley of Peru. Unfortunately, the seed germination The next step in the quinoa EPB is to plant the selected quinoa lines at different locations and altitudes in the province of Cañar to evaluate yield performance and disease resistance. Moreover, APROSANAMY is interested in introducing the color panicle quinoa lines such as red, yellow, and orange close to archaeological sites where tourists are keen to see quinoa diversity.

from the lines was very low and drought and frost conditions caused the loss of the trial;

In October 2019, Kevin Murphy, Nicolas Pichazaca, Cristina Ocaña Gallegos (a new graduate student at WSU) planted 37 quinoa lines from the previous year's selections. The trial was affected by high pressure of downy mildew and lines derived from

however, new plantings are planned in the future with the same lines.

"Puno"/"Pasankalla" showed high resistance to this pathogen.

**Table 7.** Timeline of APROSANAMY and WSU collaboration, including dates, locations, and activities.

#### **8. Conclusions**

Ecuador was considered the third largest quinoa producer globally, but with more recent expansion of this crop in other countries it is hard to assume that this statement is still true. The current quinoa production in Ecuador is around 4500 t per year and the Central provinces (Chimborazo and Cotopaxi) are the major producers. Participatory research has been carried out on quinoa for many years, mainly in the province of Bolívar. The National Agricultural Research Institute of Ecuador (INIAP) has released all the Ecuadorian quinoa varieties and new varieties are expected to be released soon from its hybridization program. The European Committee for Training and Agriculture (CEFA) has been working in the province of Chimborazo to support quinoa production; its main input was to develop a quinoa technical committee. On the other hand, new insects have been reported in quinoa fields, many of which are predators and parasitoids. Downy mildew (*Peronospora variabilis*) is the only damaging quinoa disease in Ecuador and durable resistance is the main objective of the quinoa breeding program at INIAP.

Ecuadorian quinoa is highly diverse contrary to previously thought. Wild quinoa has been poorly studied in Ecuador and there are no strong molecular studies showing its origin and identification; thus, new molecular works are necessary and must include wild quinoa and more landraces. On the other hand, new initiatives have begun to adapt quinoa to tropical coastal areas. Great progress is occurring in the province of Los Rios with the start of a new quinoa hybridization program at the State Technical University of Quevedo. In addition, Ecuador has developed different quinoa transformation strategies to link farmers and agribusiness enterprises, and Ecuadorian universities have conducted several research studies on nutrition and food sciences in the last five years.

A great effort has been made in the last five years to increase quinoa diversity in the Cañar province through an evolutionary participatory breeding project between Associa-

tion of Producers of Seeds and Nutritious Andean Foods Mushuk Yuyay (APROSANAMY) and Washington State University (WSU). New quinoa colors, bigger seed size, and different panicle shapes have been introduced as well as early maturing quinoa. These new traits will help Cañar quinoa producers to achieve higher grain production and avoid late season rains and unpredictable droughts.

The current information presented in this article suggests that quinoa research and production in Ecuador is on the right track; however, it will be difficult to compete with the big technologies of countries such as China, Australia, and Spain where quinoa production has been recently rebounding. As a country, Ecuador needs to reinforce local consumption and internal demand for quinoa.

**Author Contributions:** L.H. led the manuscript planning, reported information about quinoa genetic diversity and contributed in the Case Study; A.L. contributed with CEFA information and results; C.C. (Carlos Carpio), C.C. (Carmen Castillo), and J.O. provided significant information about quinoa pests and disease; D.M. collected the pests in quinoa fields; C.M. (Camilo Mestanza) contributed with information about quinoa adaptation in tropical areas; A.M. provided the quinoa breeding strategies from INIAP; E.V. contributed with information about processing quinoa; C.M. (Carlos Monar) synthesized the information on participatory research in Bolívar; N.P. conducted the quinoa trials with APROSANAMY; K.M. edited the manuscript and provided significant additional information. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by IBED University of Amsterdam (accession no. R.2323.0106). The WSU-APROSANAMY research was supported in part by USDA NIFA Hatch funds (accession no. 1014754). The insect inventory was supported by CEFA.

**Acknowledgments:** We acknowledge Jorge Cajarmarca and Victor Lema for providing the updated quinoa production data and for assisting us with Figure 1. We kindly thank all the Kichwa Kañari farmers that helped to plant and maintain the trials in the case study with WSU and APOSANAMY. In addition, we thank to Annie Pollard and Adam Alans for their comments and suggestions to our manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

#### **References**

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**Author details**

Flora Thanadar Ajmiree Dr. Sirajul Islam Medical College and Hospital, Dhaka, Bangladesh

\*Address all correspondence to<EMAIL_ADDRESS>
© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


**2. Prevalence of smoking in Nigeria**

Globally, it is estimated that the number of smokers will increase from the present prevalence of 1.3 billion to 1.6 billion people in 2025. Its associated mortality is estimated to increase to 8.3 million persons in 2030 from 4.8 million persons in 2006 [12]. In 1990, Obot reported a prevalence of 26.8% of current smokers and 4.7% of past smokers among Nigerian adults [13]. According to the 2012 GATS conducted in Nigeria, the overall prevalence of adults who currently smoked was 3.7% [(3.1 million people): 7.2% - males; 0.3% - females)] [14]. The average age at initiation of daily smoking, according to the report showed that majority began after 16 years old [14]. More recent studies among medical, pharmacy and nursing students in Southwest Nigeria had life time prevalence of 17.9% and 5.04% for lifetime and current smokers [15]. The undergraduate university students study in Ilorin, North-central

**137**

*Smoking and Non-Communicable Diseases in Sub-Saharan Africa: The Nigeria Scenario*

Nigeria recorded a similar result, 17.1 and 5.7 prevalence for lifetime and current smokers respectively [16]. The male to female prevalence ratio among current smokers were 3.8:1, male 7.7% and female 2.0%. The mean age at initiation of smoking for males (15.5 ± 2.9, range 10–22 years) was not significantly different from that of females (15.6 ± 3.3, range 10–19 years). A common factor in all the Nigerian studies is male predominance among all categories of smokers [9, 13, 15, 16]. The gender difference may be attributed to societal perception as most African communities see smoking as a sign of masculinity or even specific to manhood and vigour, while social values discourages smoking among women. This is also true in some other African studies such as Ghana [17] and Sudan [18]. Few Nigerian studies and findings from systematic review studies conducted across Sub-Saharan African countries shows no consistent disparity in smoking prevalence between rural and urban populations [19, 20]. Hence, tobacco control policies should be strengthened across all Nigerian societies regardless of geography or existing health or socioeconomic inequalities.

A substantial body of literature has emerged over the last few decades which examined the determinants of smoking behaviour in an economic framework of demand incorporating cigarette prices. Most studies in Nigeria were focused mainly on the determinants without much emphasis on the effect of cigarette pricing. Some of the determinants highlighted include the age of onset, peer group, parental influences, media influence etc. The Nigeria climate and weather favours the cultivation of tobacco in large commercial scale, especially in the South-western part of the country. This agricultural setting may influence tobacco smoking, but little is known about the influence of tobacco leave plantation (agricultural setting) on the incidence and prevalence of tobacco among children

One important determinant of cigarette smoking with perhaps the highest immediate and long term consequences is the age. Early age at debut implies that the smoker will not only have longer time over which his/her tolerance levels can increase but also that the period of exposure to cigarette smoking with subsequent complications will be high. On the average, at the turn of thirty years of age, the rate of decline in the functional capacities of human organ-system is at about 0.1% annually. This modest decline is lost and the downward trend as high as 1% annual decline is seen in those with one form of existing morbidities or harmful lifestyle

Age of smoking debut is around 15 years in Nigeria and by age 17, a persistent smoking pattern is already established and a significant 15% smoking prevalence among the adolescents [21, 22]. The male to female prevalence ratio among current smokers were 3.8:1, male 7.7% and female 2.0%. The mean age at initiation of smoking for males (15.5 ± 2.9, range 10–22 years) was not significantly different from that of females (15.6 ± 3.3, range 10–19 years) [16]. The driving force for the onset age of smoking among Nigerian children depends on the population being under study, whether out-of-school youths or in-school youths. For the out-of-school youths, psychosocial factors such as belonging to a polygamous home, low level of fathers' education, feeling loneliness in the face of weak family bonds and harsh survival realities plays an initial dominant factor, coupled with peer pressure with the attendant high prevalence of smoking among the group [20, 23]. Since these

*DOI: http://dx.doi.org/10.5772/intechopen.96693*

**3. Determinants of cigarette smoking**

and adults in Nigeria.

practices such as cigarette smoking.

**3.1 Age**

*Smoking and Non-Communicable Diseases in Sub-Saharan Africa: The Nigeria Scenario DOI: http://dx.doi.org/10.5772/intechopen.96693*

Nigeria recorded a similar result, 17.1 and 5.7 prevalence for lifetime and current smokers respectively [16]. The male to female prevalence ratio among current smokers were 3.8:1, male 7.7% and female 2.0%. The mean age at initiation of smoking for males (15.5 ± 2.9, range 10–22 years) was not significantly different from that of females (15.6 ± 3.3, range 10–19 years). A common factor in all the Nigerian studies is male predominance among all categories of smokers [9, 13, 15, 16]. The gender difference may be attributed to societal perception as most African communities see smoking as a sign of masculinity or even specific to manhood and vigour, while social values discourages smoking among women. This is also true in some other African studies such as Ghana [17] and Sudan [18]. Few Nigerian studies and findings from systematic review studies conducted across Sub-Saharan African countries shows no consistent disparity in smoking prevalence between rural and urban populations [19, 20]. Hence, tobacco control policies should be strengthened across all Nigerian societies regardless of geography or existing health or socioeconomic inequalities.


**4. Experimental Verification**

To verify the feasibility of this method, the AE source location experiment is carried out in this paper. The acoustic wave is collected by a *DS5-16C Holographic Acoustic Emission Signal Analyzer* (made by Beijing SoftLand Scientific and Technology Co., Ltd., Beijing, China). AE sources are generated by pencil-lead breaks. The HB pencil lead is 0.5 mm in diameter, and the pencil lead is broken at 30◦ on the surface of the specimen, according to the requirements of *Metal Pressure Vessel Acoustic Emission Testing and Result Evaluation (GB/T18182*—*2000)*. The granite specimen that is 200 mm × 179 mm × 84 mm in size and an average velocity of 4600 m/s is used as a monitoring system. Sixteen RS-2A piezoelectric ceramic resonant sensors with the coordinates of (10, 10, 84), (190, 10, 84), (190, 170, 84), (12, 170, 84), (0, 80, 74), (110, 0, 74), (200, 80, 74), (90, 180, 74), (0, 170, 10), (0, 90, 10), (10, 0, 10), (100, 0, 10), (190, 0, 10), (200, 90, 10), (190, 180, 10), and (100, 180, 10) (in mm) respectively are mounted on the surface of the monitoring system. Sensors are numbered as *Si* (*i* = 0, 1, ···, 15)

according to the arrival orders of the AE signals, and the nearest sensor *S*0 from the AE source is regarded as the reference sensor. Later, 15 TDOA measurements *ti* (*i* = 1, 2, ···, 15) between the sensor pairs of *S*0 and *Si* are obtained. In addition, there are four AE sources generated by pencil-lead breaks, and their coordinates are *P* (80, 120, 84), *Q* (160, 60, 84), *R* (0, 120, 42), and *T* (120, 0, 42) respectively. Before signal acquisition, the voltage threshold of each channel is set as 10 mv, and the preamplifier gain is 40 dB.

Figure 4 shows the received AE waveforms by two sensors, in which *t*0 and *t*2 are the arrival times at sensor *S*0 and sensor *S*2, respectively. Then, TDOA measurement is formed by using the arrival times at the sensor pair *S*0 and *S*2, i.e., Δ*t*2 = *t*2 − *t*0. The arrival times of the acoustic waves are picked manually according to the waveform diagram to ensure a high picking quality.

**Figure 4.** Acoustic emission (AE) signals and arrival times at different sensors.


*Article* **Real-Time Hyperspectral Data Transmission for UAV-Based Acquisition Platforms**

**José M. Melián \*, Adán Jiménez, María Díaz, Alejandro Morales, Pablo Horstrand, Raúl Guerra, Sebastián López and José F. López**

> Institute for Applied Microelectronics (IUMA), University of Las Palmas de Gran Canaria (ULPGC), 35001 Las Palmas, Spain<EMAIL_ADDRESS>(A.J<EMAIL_ADDRESS>(M.D<EMAIL_ADDRESS>(A.M<EMAIL_ADDRESS>(P.H<EMAIL_ADDRESS>(R.G<EMAIL_ADDRESS>(S.L<EMAIL_ADDRESS>(J.F.L.)

**\*** Correspondence<EMAIL_ADDRESS>
**Abstract:** Hyperspectral sensors that are mounted in unmanned aerial vehicles (UAVs) offer many benefits for different remote sensing applications by combining the capacity of acquiring a high amount of information that allows for distinguishing or identifying different materials, and the flexibility of the UAVs for planning different kind of flying missions. However, further developments are still needed to take advantage of the combination of these technologies for applications that require a supervised or semi-supervised process, such as defense, surveillance, or search and rescue missions. The main reason is that, in these scenarios, the acquired data typically need to be rapidly transferred to a ground station where it can be processed and/or visualized in real-time by an operator for taking decisions on the fly. This is a very challenging task due to the high acquisition data rate of the hyperspectral sensors and the limited transmission bandwidth. This research focuses on providing a working solution to the described problem by rapidly compressing the acquired hyperspectral data prior to its transmission to the ground station. It has been tested using two different NVIDIA boards as on-board computers, the Jetson Xavier NX and the Jetson Nano. The *Lossy Compression Algorithm for Hyperspectral Image Systems* (HyperLCA) has been used for compressing the acquired data. The entire process, including the data compression and transmission, has been optimized and parallelized at different levels, while also using the Low Power Graphics Processing Units (LPGPUs) embedded in the Jetson boards. Finally, several tests have been carried out to evaluate the overall performance of the proposed design. The obtained results demonstrate the achievement of real-time performance when using the Jetson Xavier NX for all the configurations that could potentially be used during a real mission. However, when using the Jetson Nano, real-time performance has only been achieved when using the less restrictive configurations, which leaves room for further improvements and optimizations in order to reduce the computational burden of the overall design and increase its efficiency.

**Keywords:** real-time compression; on-board compression; real-time transmission; hyperspectral images; UAVs