*Comment*

**Historicizing Migration and Displacement: Learning from the Early Roman Empire in the Time of the Nation-State. Response to Lachenicht, Susanne. Learning from Past Displacements? The History of Migrations between Historical Specificity, Presentism and Fractured Continuities.** *Humanities* **2018,** *7***, 36**


2.3.3. Basis-Set Choice

Practical application of the methods discussed above requires making the additional choice of a basis set for the wave-function expansion, which has a direct impact on the quality of the results. In this case, again one needs to make a compromise between the computational cost and desired accuracy. Most common recent choices in ESIPT studies seem to be favoring the cc-pVTZ [91] basis set from the Dunning family on the one hand [3,33,39,40,48], and different variants of the Pople 6-311 G(d,p) [92] basis set, on the other [36,72,73]. The latter direction finds its support in a general study by Laurent et al. [93], in which the basis-set effect on vertical excitation energy calculations was investigated. On the grounds of reported results, however, it is not easy to make definite ESIPT-targeted recommendations for the basis-set choice since both system and ES-specific effects come into play [93].


*Article* **WUE and CO2 Estimations by Eddy Covariance and Remote Sensing in Different Tropical Biomes**

**Gabriel B. Costa 1,2,3,\*, Cláudio M. Santos e Silva 2,4, Keila R. Mendes 4, José G. M. dos Santos 5, Theomar T. A. T. Neves 6, Alex S. Silva 6, Thiago R. Rodrigues 7, Jonh B. Silva 8, Higo J. Dalmagro 9, Pedro R. Mutti 2,4, Hildo G. G. C. Nunes 10, Lucas V. Peres 6, Raoni A. S. Santana 6, Losany B. Viana 6, Gabriele V. Almeida 6, Bergson G. Bezerra 2,4, Thiago V. Marques 11, Rosaria R. Ferreira 4, Cristiano P. Oliveira 2,4, Weber A. Gonçalves 2,4, Suany Campos 2 and Maria U. G. Andrade 2**

	-<EMAIL_ADDRESS>(L.B.V<EMAIL_ADDRESS>(G.V.A.) Laboratório de Ciências Atmosféricas, Universidade Federal de Mato Grosso Do Sul, Grande
	- Campo 79070-900, Brazil<EMAIL_ADDRESS>Programa de Pós-Graduação em Física Ambiental, Instituto de Física, Universidade Federal de Mato Grosso, Cuiabá 78060-900, Brazil<EMAIL_ADDRESS>
**Abstract:** The analysis of gross primary production (GPP) is crucial to better understand CO2 exchanges between terrestrial ecosystems and the atmosphere, while the quantification of water-use efficiency (WUE) allows for the estimation of the compensation between carbon gained and water lost by the ecosystem. Understanding these dynamics is essential to better comprehend the responses of environments to ongoing climatic changes. The objective of the present study was to analyze, through AMERIFLUX and LBA network measurements, the variability of GPP and WUE in four distinct tropical biomes in Brazil: Pantanal, Amazonia, Caatinga and Cerrado (savanna). Furthermore, data measured by eddy covariance systems were used to assess remotely sensed GPP products (MOD17). We found a distinct seasonality of meteorological variables and energy fluxes with different latent heat controls regarding available energy in each site. Remotely sensed GPP was satisfactorily related with observed data, despite weak correlations in interannual estimates and consistent overestimations and underestimations during certain months. WUE was strongly dependent on water availability, with values of 0.95 gC kg−1 H2O (5.79 gC kg−1 H2O) in the wetter (drier) sites. These values reveal new thresholds that had not been previously reported in the literature. Our findings have crucial implications for ecosystem management and the design of climate policies regarding the conservation

**Citation:** Costa, G.B.; Santos e Silva, C.M.; Mendes, K.R.; dos Santos, J.G.M.; Neves, T.T.A.T.; Silva, A.S.; Rodrigues, T.R.; Silva, J.B.; Dalmagro, H.J.; Mutti, P.R.; et al. WUE and CO2 Estimations by Eddy Covariance and Remote Sensing in Different Tropical Biomes. *Remote Sens.* **2022**, *14*, 3241. https://doi.org/10.3390/rs14143241

7

8

**\*** Academic Editors: Xiaolin Zhu, Xuanlong Ma, Jiaxin Jin, Yuke Zhou and Qiaoyun Xie

Received: 30 May 2022 Accepted: 23 June 2022 Published: 6 July 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

of tropical biomes, since WUE is expected to change in the ongoing climate change scenario that indicates an increase in frequency and severity of dry periods.

**Keywords:** gross primary production; evapotranspiration; water use efficiency


**2. Surgical technique**

With the patient placed supine in neutral position, the surgeon and first assistants stand on left and the laparoscopic tower is situated on the right. Second assistant, if present, stand on the right. It is important that the patient is well secured to the operating table to avoid incidents during bed movement.

After surgical site disinfection, the pneumoperitoneum is established using open technique (our preferred method) or Veress needle. The first trocar is placed next to the navel. Once pneumoperitoneum has reached target pressure (12 mmHg), the exploratory laparoscopy is performed in order to assess the presence of carcinomatosis or metastases to solid organs missed by imaging on pre-operative staging, which may preclude tumor resectability. Two working trocar for surgeon are subsequently placed: one (10 mm) in the left upper quadrant and the other (10 mm) in the left lower quadrant. A fourth trocar (5 mm) can be positioned in right middle quadrant for further assistance (**Figure 1**).

Sliding and left shifting of the patient in Trendelenburg positioning (i.e. head lower than legs) facilitates optimal exposure of the operating field. This leads to a shift of greater omentum over the stomach and small bowel 'descent' towards the left upper quadrant allowing adequate exposure of cecum, ascending colon, right portion of mesocolon, ileocolic vessels and right colic vessels.

**107**

**Figure 3.**

*Dissection of colon from abdominal wall.*

*Laparoscopic Right Colectomy. Intracorporeal Anastomosis Is Associated with Better Outcome*

Using laparoscopic forceps, the assistant lifts up the ascending colon to expose the right portion of mesocolon that is straightened by the surgeon: this step allows

In case of malignant disease, it is mandatory to performed lymphadenectomy simultaneously with the resection of vascular stem. In order to do that, ileocolic and

Once vascular stem has been sectioned, visceral peritoneum is cut on ileocolic vessels axis in front of duodenum, so the colic dissection can be performed under a "tent" formed by Toldt's fascia and prerenal fascia from medial-to-lateral. The dissection must be continued up to cecum in distal direction and up to hepatic flexure in cranial direction paying attention to avoid to open retroperitoneum and

This procedure is continued until the horizontal part of the duodenum comes into view. The hepatocolic ligament is sectioned to allow separation of the ascending colon from the duodenum. Access into the omental bursa is facilitated by gentle caudal retraction of the transverse colon and incision of the gastrocolic ligament. Partial removal of the mesotranverse colon is performed towards the right

In this way the colon limb can be eviscerated or approached in a tension-free manner. At this point, using laparoscopic stapler, colon and ileum are sectioned

Until this moment, surgical procedure is the same for both totally intracorporeal and extracorporeal (i.e. with bowel transection and anastomosis performed out of

*DOI: http://dx.doi.org/10.5772/intechopen.93996*

visualization of ileocolic vessels (**Figure 2**).

to damage genital vessels or ureter (**Figure 3**).

(**Figure 4**) and the specimen is extracted using endobag.

colonic angle.

abdomen).

**Figure 2.** *A-artery, V-vein.*

right colic vessels must be ligated and sectioned at their origin.

**Figure 1.** *Trocars position.*

*Laparoscopic Right Colectomy. Intracorporeal Anastomosis Is Associated with Better Outcome DOI: http://dx.doi.org/10.5772/intechopen.93996*

Using laparoscopic forceps, the assistant lifts up the ascending colon to expose the right portion of mesocolon that is straightened by the surgeon: this step allows visualization of ileocolic vessels (**Figure 2**).

In case of malignant disease, it is mandatory to performed lymphadenectomy simultaneously with the resection of vascular stem. In order to do that, ileocolic and right colic vessels must be ligated and sectioned at their origin.

Once vascular stem has been sectioned, visceral peritoneum is cut on ileocolic vessels axis in front of duodenum, so the colic dissection can be performed under a "tent" formed by Toldt's fascia and prerenal fascia from medial-to-lateral. The dissection must be continued up to cecum in distal direction and up to hepatic flexure in cranial direction paying attention to avoid to open retroperitoneum and to damage genital vessels or ureter (**Figure 3**).

This procedure is continued until the horizontal part of the duodenum comes into view. The hepatocolic ligament is sectioned to allow separation of the ascending colon from the duodenum. Access into the omental bursa is facilitated by gentle caudal retraction of the transverse colon and incision of the gastrocolic ligament. Partial removal of the mesotranverse colon is performed towards the right colonic angle.

In this way the colon limb can be eviscerated or approached in a tension-free manner. At this point, using laparoscopic stapler, colon and ileum are sectioned (**Figure 4**) and the specimen is extracted using endobag.

Until this moment, surgical procedure is the same for both totally intracorporeal and extracorporeal (i.e. with bowel transection and anastomosis performed out of abdomen).

**Figure 2.** *A-artery, V-vein.*

*Colorectal Cancer*

surgical safety.

**2. Surgical technique**

trials showed comparable outcomes between open and laparoscopic surgery in

From a technical point of view, various operative factors - such as extent of resection, number of lymph nodes sampled, length of bowel and mesentery resected, and bowel margins – do not differ significantly between patients who underwent laparoscopic surgery and those who underwent open colectomy. With regards to intra-abdominal staging accuracy, laparoscopy allied with solid-organ

Laparoscopic right hemicolectomy is currently considered the standard of care

This chapter describes the technique for laparoscopic right colectomy technique, with a focus on ileo-colic anastomosis, highlighting the differences between intracorporeal and extracorporeal anastomosis fashions in terms of clinical outcome and

With the patient placed supine in neutral position, the surgeon and first assistants stand on left and the laparoscopic tower is situated on the right. Second assistant, if present, stand on the right. It is important that the patient is well secured to the

After surgical site disinfection, the pneumoperitoneum is established using open technique (our preferred method) or Veress needle. The first trocar is placed next to the navel. Once pneumoperitoneum has reached target pressure (12 mmHg), the exploratory laparoscopy is performed in order to assess the presence of carcinomatosis or metastases to solid organs missed by imaging on pre-operative staging, which may preclude tumor resectability. Two working trocar for surgeon are

subsequently placed: one (10 mm) in the left upper quadrant and the other (10 mm) in the left lower quadrant. A fourth trocar (5 mm) can be positioned in right middle

Sliding and left shifting of the patient in Trendelenburg positioning (i.e. head lower than legs) facilitates optimal exposure of the operating field. This leads to a shift of greater omentum over the stomach and small bowel 'descent' towards the left upper quadrant allowing adequate exposure of cecum, ascending colon, right

terms of overall survival and disease-free survival [3].

imaging offers adequate staging information [4].

in benign and malignant right colon disease [2].

operating table to avoid incidents during bed movement.

portion of mesocolon, ileocolic vessels and right colic vessels.

quadrant for further assistance (**Figure 1**).

**106**

**Figure 1.** *Trocars position.*

**Figure 3.** *Dissection of colon from abdominal wall.*


**7. Radial artery grafts as a second arterial conduit**

tively, patient scores in all areas of the questionnaire were significantly lower than that of the results of the standardized Danish population. Post-operatively, both revascularization groups showed significant improvement in all areas at 3 months and 11 months, with the TAR group showing improvement in the 'social functioning' category that was significantly higher than the conventional revascularization group. There was no significant difference in postoperative improvement in the categories 'physical component summary,' 'bodily pain,' and

**6. Incidence of sternal wound infection, subset of patients benefiting from BIMA, IMA harvesting techniques, and operative time in BIMA CABG**

One of the main concerns amongst surgeons regarding the use of BIMA in CABG procedures is the occurrence of sternal wound infections (SWI). When both internal mammary arteries are harvested, blood supply to the sternum may be more severely compromised than in single IMA procedures, thus increasing the risk for developing SWI. Various pre-operative and intraoperative techniques have been used to prevent the incidence of SWI, such as the use of prophylactic antibiotics, double gloving, and skeletonized IMA harvesting [7]. Skeletonized IMA harvesting is thought to preserve the collateral blood supply to the sternum and reduce

Patients who are insulin-dependent diabetics, morbidly obese, or who have severe COPD are at a higher risk of developing SWI (DSWI = deep sternal wound infection, definition varies)

In a study performed by Pevni *et al.*, 1,515 consecutive patients underwent CABG procedures with skeletonized BIMA grafting. In earlier studies, the authors state that, in their past experience, patients with chronic lung disease, diabetic females, and obese diabetics repre‐ sented absolute contraindications to BIMA grafting for CABG procedures because of the risk of SWI. However in this study, the authors found that there was no evidence of a relationship between diabetes mellitus and DSWI in patients receiving skeletonized BIMA grafts, even with

In a meta-analysis of 13 studies regarding BIMA CABG procedures and the harvesting technique for the IMAs, Saso *et al.* found that skeletonizing the IMA as opposed to harvesting it in a pedicled manner lowered the incidence of SWI by 60%. An even greater benefit of skeletonized harvesting was noted in groups at an increased risk for SWI, such as in diabetic patients. The authors also found that these decreased rates of SWI applied to the entire

Kurlansky *et al.* found a slightly higher incidence of SWI amongst diabetic patients receiving BIMA grafting compared to diabetic patients receiving LIMA grafting, but the difference was not significant. However, amongst patients receiving BIMA grafts, the presence of diabetes did affect the occurrence of SWI. This suggests that, while the presence of diabetes mellitus

and, in general, bilateral harvesting of the IMAs is avoided in these patients [7, 8].

a prevalence of diabetes mellitus of 34% in their patient population [23].

spectrum of sternal infections, including mediastinitis [22].

'vitality' between the two revascularization groups [21].

the risk of infection [22].

124 Artery Bypass

The success of the LIMA in CABG procedures has lead surgeons to search for other arterial conduits. The radial artery has become a popular choice as an additional arterial conduit in attempts to achieve total arterial revascularization of the myocardium. There are numerous advantages to using the radial artery, including its long length, exposure to systemic blood pressures, and the fact that it is seldomly affected by atherosclerosis. However, the radial artery has a thicker tunica media, which is thought to contribute to its greater vasoconstrictor response than the IMA and could possibly lead to vessel occlusion. Thus, care must be taken during operative harvesting and the use of calcium-channel blockers may ameliorate a vasospastic response [24].

Like the LIMA, the radial artery has been shown to have significantly better short and longterm patency results and outcomes than vein grafts. In the radial artery patency study (RAPS), Desai *et al*. randomized 561 patients to receive a radial artery graft to either the inferior (right) coronary territory or to the lateral (circumflex) coronary territory, with a saphenous vein graft anastomosed to the opposite territory in each group as a control. All patients also received a LIMA graft to the LAD, with the main endpoint of the study being 1-year angiographic complete occlusion of the radial artery versus saphenous vein. In this definition of occlusion, grafts displaying the string-sign would be considered patent. At the mean follow-up of 10.9 months, 13.6% of saphenous vein grafts were completely occluded and 8.6% of radial artery grafts were completely occluded (p = 0.009). The authors also found that the patency of radial artery grafts depends on the severity of the native vessel stenosis, with better patency results corresponding with higher grades of stenosis. Thus, the authors recommend using the radial artery for the most highly occluded coronary vessel after the LAD [25].

In a follow-up to the original RAPS study, Deb *et al.* extended the mean angiographic followup time to 7.7 years, with 269 patients of the original 561 undergoing late angiography. The primary endpoint was functional graft occlusion; vessels displaying narrowing or reduced flow were considered occluded as well as vessels that were completely occluded. 12.0% of radial artery grafts were determined to be functionally occluded compared with 19.7% of saphenous vein grafts (p = 0.03). For the secondary endpoint of complete occlusion, 8.9% of radial artery grafts were completely occluded compared with 18.6% of saphenous vein grafts (p = 0.002) [26].

Ruttman *et al.* studied 1,001 patients undergoing CABG procedures either receiving RIMA grafts or radial artery grafts as second conduits after LIMA grafts with or without concomitant saphenous vein grafts added when necessary. Propensity-score matched analysis was performed on the two patient groups to examine the short and long-term outcomes of BIMA grafting versus LIMA plus radial artery grafting. Overall, the evidence provides strong support for the use of the RIMA over the radial artery as a second choice arterial conduit. Radial artery graft occlusion and disease rates were significantly higher than both IMA and saphenous vein anastomoses, with occlusion/disease rates of 37.9%, 10.2%, and 20.9%, respectively. Survival rates for BIMA grafting were 98.9% at 1, 3, and 5 years post-operatively, compared with rates for the radial artery group of 96.8%, 96.3%, and 93.0% at the same postoperative years. The BIMA group also had significantly higher rates of major cardiac and cerebrovascular events-free survival than the radial artery group at the same yearly intervals

Total Arterial Revascularization in Coronary Artery Bypass Grafting Surgery

http://dx.doi.org/10.5772/54866

127

In a 10-year prospective, randomized trial, Hayward *et al.* examined angiographic out‐ comes of patients receiving either a radial artery, RIMA, or saphenous vein graft to the second largest coronary target after the LAD, which was grafted with the LIMA. Patients were randomized to two groups: those less than 70 years of age received either a radial artery or RIMA as the second arterial conduit, and those greater than 70 years of age re‐ ceived either a radial artery or saphenous vein. At a mean follow up of 5.5 years, a total of 350 patients between the two groups had angiography performed. In the first group, Kaplan-Meier estimates of graft patency were 89.8% for the radial artery and 83.2% for the RIMA (p = 0.06). In the second group, patency estimates were 90.0% for the radial ar‐ tery and 87.0% for the saphenous vein (p = 0.29). With no significant difference in the pa‐ tency rates between the conduits in each of the two groups, the results show that the choice of conduit for the second largest coronary target does not significantly affect pa‐

The clinical benefits of RIMA and radial artery use have been established, and many studies have indirectly examined the results of TAR in patients receiving BIMA or radial artery grafts without the need of concomitant saphenous vein grafts. However, few studies have specifically

In a prospective study by Muneretto *et al.,* 200 patients over 70 years of age were randomized into two groups either receiving TAR or conventional CABG (LIMA to LAD with additional saphenous vein grafts if needed). Even though 31% of patients in the TAR group received BIMA grafts, the incidence of perioperative sternal wound complica‐ tions was found to be 1% in both groups. At the mean follow up of 15 months, the inci‐ dence of cardiac-related events (MI, angina, coronary angioplasty, and graft occlusion) was significantly higher in the conventional CABG group compared to patients receiving

tency, giving surgeons flexibility in their revascularization plans [33].

compared the clinical outcomes of TAR to conventional CABG procedures.

**9. Total Arterial Revascularization (TAR)**

post-operatively [32].

Zacharias *et al.* compared 6-year outcomes in propensity matched CABG patients receiving LIMA to LAD grafts who also received either radial artery grafts or vein grafts only. The authors found that mortality rates were 67% and 98% greater in vein patients than in radial artery patients after 1 and 6 years, respectively. While LIMA patencies were always signifi‐ cantly greater than both radial and vein patencies, 6-year radial graft patencies were system‐ atically greater than that of vein grafts, although the results failed to reach statistical significance. Overall, the use of the radial artery as a second arterial conduit in LIMA to LAD CABG patients is associated with improved long-term survival [27].

Collins *et al.* compared 142 patients receiving either radial artery or saphenous vein grafted to the left circumflex coronary artery, with the end point being 5-year angiographic patency. 98.3% of radial artery grafts and 86.4% of saphenous vein grafts were found to be patent after the 5-year angiographic study of 103 patients (p = 0.04). The rate of graft narrowing was also significantly less in radial artery grafts compared to vein grafts, with narrowing occurring in 10% of patent radial artery grafts and 23% of patent saphenous vein grafts (p = 0.01) [28].

A smaller study by Cameron *et al.* also examined the 5-year angiographic patency results of radial artery grafts. Grafts that displayed a string sign were considered not patent. With a radial artery graft patency rate of 89%, the authors found that the radial artery had a patency rate similar to that of other grafts, although the study was too small to determine whether or not this result was statistically significant [29]. Acar *et al.* report similar results for radial artery graft patencies when compared to the LIMA [30].

Not all studies of radial artery use have been favorable. In a review of 310 patients receiving radial artery grafts between 1996 and 2001, Khot *et al.* found significantly lower patency rates for radial artery grafts when compared to IMA grafts, and similar patency rates when compared to saphenous vein grafts after a mean follow up of 565 ± 511 days. Patency rates of radial artery grafts, LIMA grafts, and saphenous vein grafts were 51.3%, 90.3%, and 64.0%, respectively. While patency rates were similar between radial artery and saphenous vein grafts, there was a significantly higher incidence of severe disease in radial artery grafts (p = 0.0003). Women were also found to have significantly lower radial artery patency rates than men [31]. However, Desai *et al.* specifically note that this study did not use randomized controls, standardized surgical methods, concurrent pharmacology, or routine angiographic follow-up that could lead to potential bias [25].


**3.2 Reconfigurable PV module**

It is shown in different research work the ways different fixed PV cell topologies mitigate the effect of partial shading and mismatch [28–31]. The usage of bypass diode achieves the effectiveness of fixed topologies. However, a fault in the bypass diodes can make various topologies for creating PV modules ineffective. Compared to using bypass diode, a novel complementary metal-oxide-semiconductor (CMOS) switch embedded PV module is proposed [32]. Thus having CMOS based switches the PV modules configuration, i.e., the number of PV cells in series vs. the number of PV cells in parallel, can be changed in real time [12, 32] in case of a fault in PV cells or partial shading condition. A CMOS embedded PV module is shown in **Figure 9**. The circuit diagram of the switches used is presented in detailed in [33].

In [27], it is presented that reconfigurable PV modules are much better in tackling the effect partial shading condition. However, it is also shown on the resistance of metal oxide semiconductor field-effect transistor (MOSFET) can reduce the

**Figure 7.**

*The PV module connected in BL topology. a) the configuration of PV module is 4 × 5 b) I-V characteristics of PV module c) P-V characteristics of PV module under different shading condition.*

#### **Figure 8.**

*The PV module connected in HC topology. a) the configuration of PV module is 4 × 5 b) I-V characteristics of PV module c) P-V characteristics of PV module under different shading condition.*

#### **Figure 9.**

*CMOS switch embedded PV module. A group of four transistors are connected in series by turning ON and OFF CMOS based transistors.*

effectiveness of the CMOS embedded PV module. Hence, it is a necessity to develop a modeling technique for reconfigurable PV modules for further development and deployment of their usage in various applications. Three different types of MOSFETs are used for modeling the reconfigurable, which is presented in **Table 2** [12].

The array decomposition for modeling the CMOS embedded PV module is shown in **Figure 10**. For simplicity, the two diodes are combined into a single diode shown in **Figure 10**. The total current generated by the reconfigurable PV module in configuration Ns × Np (number of PV cells in series x number of PV cells in parallel) is given by [33]:

$$I\_{PV} \approx N\_p \left[ I\_{ph} - I\_{d1} - I\_{d2} - \frac{B}{R\_P} \right] \tag{6}$$

$$I\_d = I\_s \left( \mathbf{e}^{\left(\frac{B}{\mathbf{A} \times \mathbf{V}\_T}\right)} - \mathbf{1} \right) \tag{7}$$

**27**

**Figure 11.**

*PV cells in series x number of PV cells in parallel).*

*Modeling of Photovoltaic Module*

**Table 2.**

**Figure 10.**

*DOI: http://dx.doi.org/10.5772/intechopen.97082*

*CMOS transistors resistance variable name and values.*

*PV cell decomposition technique for modeling CMOS embedded PV module.*

*The maximum power under different shading patterns over PV module for different configurations (number of*

**Symbol Description Value and units**

RPs ON resistance of P-type MOSFET transistor 1mΩ RT ON resistance of transmission gate transistor 1mΩ Rns ON resistance of N-type MOSFET transistor 1mΩ

$$B = \frac{\upsilon\_{pv}}{N\_S} + i\_{pv} \left( \frac{R\_S}{N\_P} + \frac{\left(N\_S - 1\right) \cdot R\_T}{N\_P \cdot N\_S} + \frac{2 \cdot R\_m}{\left(N\_P - 1\right) \cdot N\_S} \right) \tag{8}$$

In Eq. (8), the Rns is equal to RPS. It is possible to achieve it by sizing the N-type and P-type MOSFET transistor's width based on the process transconductance. The


**Author details**

Takuya Kawabata1 \* and Yoshinori Shoji2

\*Address all correspondence to<EMAIL_ADDRESS>
1 Forecast Research Department, Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan

[9] Niimura N, Sasaki T, Kimura F. Statistical relation between precipitation and precipitable water vapor obtained from the global positioning system (GPS) in Tokyo metro-

Applications of GNSS Slant Path Delay Data on Meteorology at Storm Scales

http://dx.doi.org/10.5772/intechopen.75101

159

[10] Inoue H, Inoue T. Characteristics of the water-vapor field over the Kanto District associated with summer thunderstorm activities. Scientific Online Letters on the Atmosphere:

[11] Hirahara K.Local GPS tropospheric tomography. Earth Planets and Space. 2000;**52**:935-939

[12] Noguchi W, Yoshihara T, Tsuda T, Hirahara K. Time-height distribution of water vapor derived by moving cell tomography during Tsukuba GPS campaigns. Journal of the

[13] Seko H, Nakamura H, Shoji Y, Iwabuchi T. Meso-γ scale water vapor distribution associated with the thunderstorm on 1 august 2001 estimated by the tomography method.

[14] Nakamura H, Koizumi K, Mannoji N. Data assimilation of GPS precipitable water vapor into the JMA mesoscale numerical weather prediction model and its impact on rainfall

[15] Koizumi K, Sato Y. Impact of GPS and TMI precipitable water data on mesoscale numerical weather prediction model forecasts. Journal of the Meteorological Society of Japan.

[16] Seko H, Kawabata T, Tsuyuki T, Nakamura H, Koizumi K, Iwabuchi T. Impacts of GPSderived water vapor and radial wind measured by Doppler radar on numerical prediction of precipitation. Journal of the Meteorological Society of Japan. 2004c;**82**:473-489

[17] Shoji Y. A study of near real-time water vapor analysis using a nationwide dense GPS network of Japan. Journal of the Meteorological Society of Japan. 2009a;**87**:1-18

[18] Shoji Y, Kunii M, Saito K. Assimilation of nationwide and global GPS PWV data for a heavy rain event on 28 July 2008 in Hokuriku and Kinki, Japan. Scientific Online Letters

[19] Shimada S, Seko H, Nakamura H, Aonashi K, Herring TA. The impact of atmospheric mountain lee waves on systematic geodetic errors observed using the global positioning

[20] Ishikawa, Y., Application of GPS signal delay observed by ground-based receivers, validation and upgrading of analysis-forecast system, Suuchi Yohou Kenshuu Text (Text for

[21] Ha S, Kuo Y-H, Guo Y-R, Lim G-H. Variational assimilation of slant-path wet delay measurements from a hypothetical ground-based GPS network. Part I: Comparison with

precipitable water assimilation. Monthly Weather Review. 2003;**131**:2635-2655

politan area. Tenki. 2000;**47**:635-642 (in Japanese)

Meteorological Society of Japan. 2004;**82**:561-568

on the Atmosphere: SOLA. 2009b;**5**:45-48

system. Earth, Planets and Space. 2002;**54**:425-430

NWP Training Course). 2008;**41**:53-57 (in Japanese)

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forecast. Journal of the Meteorological Society of Japan. 2004;**82**:441-452

SOLA. 2007;**3**:101-104

2004;**82**:453-457

2 Meteorological Satellite and Observation System Research Department, Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan


**Figure 4.**

#### **Figure 5.**

*Ishikawa diagram of the HPP project risks.*

#### **Figure 6.**

*Risk analysis in the MS project software (part).*

Based on the risk analysis of all project activities, the project team established that eight activities have a very high risk rate, which is why they decided to analyse these risks in more detail using the standard risk management model. For each of the eight high-risk activities, the project team determined the probability of a risk event *Pe* occurrence and a probability of consequences *Pi* and calculated the overall risk probability. The total loss *Lt* and the expected loss *Le* calculated using Eq. (2) were assessed.

The majority of risks in question result in a delay in the project and consequently in the launch of the HPP test operation. Our assessment of losses was based on data that indicated 1 day of interrupted operation of such an HPP means a loss of income of 17,600 EUR/day. Calculations for the expected losses are given in **Table 2**.

As evident from **Table 2**, some risk-related losses refer to monetary losses and others to time losses, which is why the risks related to monetary losses in terms of

**11**

in **Table 3**.

to delays (**Figure 8**).

were realised.

quences if a risk event were realised.

*Standard Risk Management Model for Infrastructure Projects*

**description**

Delay in adoption

Delay in adoption

Delay in execution

not met

Opposition of owners

Opposition of owners

Damage to existing roads

*Evaluation of losses in huge project risks relating to the erection of the HPP reservoir.*

**Designation** *Pe Pi Pe × Pi Lt* **[103**

Extra costs T3 0.7 0.5 0.35 €50 €17.5

T1 0.9 1 0.9 €320 €288

T2 0.9 1 0.9 6 months 5.4 months

T4 0.8 0.8 0.64 6 months 3.8 months

T5 0.9 0.7 0.63 2 months 1.3 months

T6 0.7 0.8 0.56 €200 €112

T7 0.7 0.6 0.42 5 months 2.1 months

T8 0.8 0.9 0.72 €750 €540

 **€ or month]**

*Le* **[103 € or month]**

extra costs (**Figure 7**) are shown in the risk map separately from the time losses due

In the risk map, in which the risks related to extra costs (**Figure 7**) are shown, four risks are identified: of those, three (T1, T6, and T8) are critical, while the T3 risk belongs to the group of noncritical ones. The project team subsequently prepared adequate measures for the critical risks to prevent or mitigate the conse-

In the risk map, in which the risks related to delays (**Figure 8**) are shown, four risks are identified as well: of those, two (T2 and T4) are critical and two (T5 and T7) belong to the noncritical risks. Again, the project team prepared adequate measures for the critical risks to prevent or mitigate the consequences if a risk event

To illustrate preparation, analysis, and assessment of further measures to mitigate the risk consequences, the T1 risk was selected, i.e., the adoption of the DPN (state spatial plan). This is the first activity in the project having a high and critical risk (particularly due to the fact that it can delay the project's execution and due to the extra costs incurred). The state spatial plan is adopted by the Government of the Republic of Slovenia upon a proposal from the ministries and in conformity with other bodies issuing permits for the placement of infrastructure projects into the space. Local communities actively participate in this process. To mitigate the consequences of the T1 risk (delay in the adoption of the DPN), the project team prepared a plan of measures in three iterations, as shown

*DOI: http://dx.doi.org/10.5772/intechopen.83389*

**No. Activity Risk**

1 Adoption of national spatial plan—DPN

2 Adoption of national spatial plan—DPN

3 Reservoir plan

4. Reservoir plan

6 Acquisition of buildings and land

7 Acquisition of buildings and land

8 Existing roads

**Table 2.**

5 Tender Conditions

*Standard Risk Management Model for Infrastructure Projects DOI: http://dx.doi.org/10.5772/intechopen.83389*

#### **Table 2.**

*Risk Management in Construction Projects*

Based on the risk analysis of all project activities, the project team established that eight activities have a very high risk rate, which is why they decided to analyse these risks in more detail using the standard risk management model. For each of the eight high-risk activities, the project team determined the probability of a risk event *Pe* occurrence and a probability of consequences *Pi* and calculated the overall risk probability. The total loss *Lt* and the expected loss *Le* calculated using

The majority of risks in question result in a delay in the project and consequently in the launch of the HPP test operation. Our assessment of losses was based on data that indicated 1 day of interrupted operation of such an HPP means a loss of income

As evident from **Table 2**, some risk-related losses refer to monetary losses and others to time losses, which is why the risks related to monetary losses in terms of

of 17,600 EUR/day. Calculations for the expected losses are given in **Table 2**.

**10**

**Figure 5.**

**Figure 6.**

*Ishikawa diagram of the HPP project risks.*

Eq. (2) were assessed.

*Risk analysis in the MS project software (part).*

*Evaluation of losses in huge project risks relating to the erection of the HPP reservoir.*

extra costs (**Figure 7**) are shown in the risk map separately from the time losses due to delays (**Figure 8**).

In the risk map, in which the risks related to extra costs (**Figure 7**) are shown, four risks are identified: of those, three (T1, T6, and T8) are critical, while the T3 risk belongs to the group of noncritical ones. The project team subsequently prepared adequate measures for the critical risks to prevent or mitigate the consequences if a risk event were realised.

In the risk map, in which the risks related to delays (**Figure 8**) are shown, four risks are identified as well: of those, two (T2 and T4) are critical and two (T5 and T7) belong to the noncritical risks. Again, the project team prepared adequate measures for the critical risks to prevent or mitigate the consequences if a risk event were realised.

To illustrate preparation, analysis, and assessment of further measures to mitigate the risk consequences, the T1 risk was selected, i.e., the adoption of the DPN (state spatial plan). This is the first activity in the project having a high and critical risk (particularly due to the fact that it can delay the project's execution and due to the extra costs incurred). The state spatial plan is adopted by the Government of the Republic of Slovenia upon a proposal from the ministries and in conformity with other bodies issuing permits for the placement of infrastructure projects into the space. Local communities actively participate in this process. To mitigate the consequences of the T1 risk (delay in the adoption of the DPN), the project team prepared a plan of measures in three iterations, as shown in **Table 3**.

**Figure 7.** *Map of project risks expressed by costs.*

**Figure 8.** *Map of project risks expressed as delay in time.*

For the anticipated measures, the project team assessed the probabilities of a risk event occurrence, a probability of impact after the adoption of a measure and the total and expected loss. Ten percent of the anticipated loss of income was determined by the project team as the value of the total loss. The calculations and results for all three iterations of measures are shown in **Table 4**.

Based on the results from **Table 4**, a risk map for the T1 risk was drawn up (delay in adopting a DPN), which is shown in **Figure 9**.

In the risk map in **Figure 9**, the threshold line denotes a still acceptable value of loss of EUR 100,000, which the project team considers to be the maximum tolerable value. T1 represents the starting situation, and there are no extra measures except warnings to the Government of the RS to start preparing a DPN for the erection of the HPP reservoir. The expected delay here will be 6 months, and the expected loss incurred by the client due to a delay in the scheduled start-up of the HPP is EUR 288,000. Point T1.1 represents a point of risk T1 in the risk map after a measure is adopted, with which the ministry responsible for infrastructure would appoint a co-ordinator to co-ordinate the preparation of the DPN. Still, a delay of 5 months is expected, while the expected loss in this case would be reduced to EUR 180,000, which still means that the risk is a critical one. Additional suggested measures, with

**13**

**Figure 9.**

which the municipalities on the territory in which the HPP reservoir will be erected, would co-ordinate among themselves and could render risk T1 noncritical, because point T1.2 lies below the threshold line of expected losses. A delay of 4 months is

*Standard Risk Management Model for Infrastructure Projects*

**Risk Risk event driver Prevention plan Impact driver Contingency plan**

Minimum 6-month delay in preparation of documentation

Minimum 5-month delay in preparation of documentation due to discrepancies within ministries

Mismatched comments between municipalities represent a further 4 months of delay

> **Total loss** *Lt* **(thousand EUR)**

**Total probability**  *Pe × Pi*

T1 0.9 1 0.9 320 288 T1.1 0.6 1 0.6 300 180 T1.2 0.4 0.8 0.32 250 80

A loss of income totalling EUR 3.2 million is anticipated

A loss of income of €3 million is anticipated, despite the appointment of a co-ordinator for the preparation of a DPN

Comments of municipalities get matched, yet a further €2.5 million loss of income is still anticipated

> **Expected loss** *Le* **(thousand EUR)**

Client should warn the government of the consequences of delay in adopting the resolution on the preparation of a DPN

Suggest that the Ministry of Infrastructure assumes co-ordination

Mismatched comments between municipalities

*Plan of measures to reduce consequences of risk in the preparation of the DPN.*

*Results of calculated impacts of the suggested measures to mitigate risk T1.*

*Risk map after the introduction of anticipated measures to mitigate risk T1.*

**Probability of impact** *Pi*

*DOI: http://dx.doi.org/10.5772/intechopen.83389*

T1 Government of the RS is often late in adopting a resolution on preparing a DPN

T11 Discrepancy in the work of ministries in the preparation of a DPN

T12 Comments of

**Risk Probability of**

**risk event** *Pe*

**Table 3.**

**Table 4.**

municipalities on the proposed DPN *Standard Risk Management Model for Infrastructure Projects DOI: http://dx.doi.org/10.5772/intechopen.83389*

#### **Table 3.**

*Risk Management in Construction Projects*

**Figure 7.**

**Figure 8.**

*Map of project risks expressed by costs.*

For the anticipated measures, the project team assessed the probabilities of a risk event occurrence, a probability of impact after the adoption of a measure and the total and expected loss. Ten percent of the anticipated loss of income was determined by the project team as the value of the total loss. The calculations and results

Based on the results from **Table 4**, a risk map for the T1 risk was drawn up (delay

In the risk map in **Figure 9**, the threshold line denotes a still acceptable value of loss of EUR 100,000, which the project team considers to be the maximum tolerable value. T1 represents the starting situation, and there are no extra measures except warnings to the Government of the RS to start preparing a DPN for the erection of the HPP reservoir. The expected delay here will be 6 months, and the expected loss incurred by the client due to a delay in the scheduled start-up of the HPP is EUR 288,000. Point T1.1 represents a point of risk T1 in the risk map after a measure is adopted, with which the ministry responsible for infrastructure would appoint a co-ordinator to co-ordinate the preparation of the DPN. Still, a delay of 5 months is expected, while the expected loss in this case would be reduced to EUR 180,000, which still means that the risk is a critical one. Additional suggested measures, with

for all three iterations of measures are shown in **Table 4**.

in adopting a DPN), which is shown in **Figure 9**.

*Map of project risks expressed as delay in time.*

**12**

*Plan of measures to reduce consequences of risk in the preparation of the DPN.*

#### **Table 4.**

*Results of calculated impacts of the suggested measures to mitigate risk T1.*

#### **Figure 9.**

*Risk map after the introduction of anticipated measures to mitigate risk T1.*

which the municipalities on the territory in which the HPP reservoir will be erected, would co-ordinate among themselves and could render risk T1 noncritical, because point T1.2 lies below the threshold line of expected losses. A delay of 4 months is

still expected, yet the expected loss is EUR 80,000, which is less than the maximum threshold value of EUR 100,000 the project team had determined for this risk.

In the project execution phase, the activities of the project must be closely monitored, and attention should be paid to the time of risk event occurrence. The project team can determine risk indicators [12] that remind them of points in time when a potential risk event might or could be expected to occur. It is not enough only to introduce measures, the situation should be constantly monitored and additional measures adopted to mitigate the impacts of risk events that occur. In the case of the erection of the HPP reservoir, the project team also constantly monitored the risk management activities and adopted adequate measures as required. The management of risks in the project in question was ultimately successful, since the HPP started operating on schedule and according to the timeline.

It is important to note that once the project was completed, the project team made a thorough analysis of their risk management strategy and identified those solutions that proved effective and successful and that would be worth using in similar projects in the future, as well as ineffective solutions that should be avoided in future projects.


**4. Mechanisms of femtosecond processing**

Understanding the physical mechanisms and processes of FSL is important, as they differ between FSL fabrication (including phase change and material removal) and traditional manufacturing methods, which are essentially determined by laser– electron interactions. Hence, the regulation of laser-electron interactions or electrons dynamics is critical to the future development of femtosecond laser manufacturing, which poses a challenge for measuring and controlling at the electron level during fabrication processes. Hence, the development of theory and observation systems must be synchronized with the development of laser fabrication methods and applications. In ophthalmic surgery, laser energy is channeled as efficiently as possible. The flap thickness is determined by placing a sterile plastic foil between the laser and the cornea. The computer keeps all corneal cuts suctioned up in a total vacuum time of <40 seconds. Laser cuts the tissue by two mechanisms; some laser pulses vaporize small amounts of tissue by photodisruption process. Vaporized tissue causes multiple intrastromal cavitation bubbles of microplasma, composed of water and carbon dioxide. The bubbles disrupt the tissue at a larger radius than the plasma created at the laser focus, which dissociates the tissue and creates a lamellar corneal dissection plane. Other lasers create a dissection plane using the desired pattern (e.g., a raster or spiral pattern), controlled by the surgeon using laser software. The nature of the cutting processes differs based on the laser-tissue interaction parameters, which include (1) Pulse energy, (2) Pulse repetition rate, (3) Pulse duration, (4) Wavelength, (5) Focusing power, (6) Focus spot shape, and (7) Spatial pulse spacing.

The laser energy used may be a high or low pulse. Lasers with high pulse energy and low frequency (with pulse energies in J and repetition rates in kHz) were used earlier (**Figure 3**). Low repetition rate and pulse overlap reduce tissue bridging. In the high pulse energy laser group, the mechanical forces drive the cutting process by the expanding bubbles, which disrupt the tissue at a larger radius than the plasma created at the laser focus. Modern FSLs use low pulse energy by shortening the pulse duration

**Figure 3.** *High pulse low-frequency energy.*

### *Fundamentals of Femtosecond Laser and Its Application in Ophthalmology DOI: http://dx.doi.org/10.5772/intechopen.106701*

or reducing the focal spot size to reduce the side effects at a given wavelength. In the low pulse energy group, high pulse frequencies are applied (MHz range), which helps achieve a cutting speed as effective as in the high energy laser group. Tissue evaporation inside the plasma effectively separates tissue without a need for secondary mechanical tearing effects [5].

Several parameters play a role in the interaction between the laser and the material, including chemical, thermal, and mechanical effects via free-electron generation. Ablation of material is caused by thermal damage resulting from impurities and defects in the samples. FSL intensities ≥1014 W/cm2 are anticipated to have the same ablation mechanisms for metals and dielectric materials. Gamaly et al. also verified the ablation threshold value and ablation velocity formula of the metal and dielectric material. This interaction also differs between metallic and non-metallic materials, as metallic materials have a large number of free electrons while non-metallic materials do not. The absorbed FSL by free photons of metallic materials results in heated photons and their collision with other electrons that transfer energy to each other and increase the interaction with the lattice. The heated lattice results in the phase transition of the material, at picosecond (10−12 s) to tens of nanoseconds (10−8 s), resulting in micro- to millisecond-scale plasma. Conversely, in non-metallic materials, electrons are bound in the valance band. The processing of FSL in non-metallic materials includes ionization and phase change. Ionization involves photoionization (which includes tunnel ionization and multiphoton ionization) and impacts ionization mechanisms. Photoionization is the main mechanism of seed-electron generation. The super-strong electromagnetic field generated by FSL reduces the Coulomb potential barrier of valence-band electrons by the tunneling effect, which results in the transfer of electrons into the conduction band and become free electrons. Multiphoton ionization refers to the absorption of multiple photon energies by the valence-band electrons, which obtain higher levels of kinetic energy, collide with other valence electrons, and transfer into the conduction band, causing a chain reaction similar to avalanche, resulting in free electrons. In other words, avalanche ionization involves free carrier absorption followed by impact ionization. As the electron's energy exceeds the conduction band minimum (more than the band-gap energy), it can ionize another electron from the valence band, which results in two excited electrons that can be heated by the laser field through free carrier absorption. This process repeats as long as the laser field is present and intense enough, leading to an electronic avalanche.

The phase change follows the first part of ionization and electron heating. In this part, the accumulation of a large number of free electrons inside the non-metallic material and the lattice-electron interaction results in the exhibition of transient metallic characteristics. In the temporal scale of picosecond (10−12 s) to tens of nanoseconds (10−8 s) and the spatial scale of tens-of-nanometers-to-tens-of-micrometers, the phase change includes thermal phase transitions (melting and gasification; when the lattice temperature rises above the melting point of the material) and non-thermal phase transitions (Coulomb explosions and electrostatic ablation; based on plasma expansion). The pump-probe technique can be used to observe the ablation processes on this temporal and spatial scale. The thermal damage depends on the pulse width and intrinsic parameters of the material (like melting point, thermal expansion coefficient, thermal conductivity coefficient, and tensile strength). As a general rule, only the fraction of energy within a laser pulse, absorbed inside the tissue, is responsible for interactions with tissue. The emitted laser energy is redistributed from a surgical laser device at the end of the tissue dissection process (**Figure 4**), and only non-linear

### **Figure 4.**

*Redistribution of energy in a pulsed laser process for tissue dissection.*

absorbed energy, which constitutes only 10–15% of FS pulses, contributes to the tissue dissection process. Similarly, in transparent dielectric materials, the laser creates free carriers inside materials by non-linear absorption processes. For transparent materials, similar models have been described (as for non-metallic materials), including multiphoton, tunnel ionization, and avalanche.

It has to be noted that the material-laser interaction is complex, and different theoretical models have been suggested for its description, including time-dependent density function theory, molecular dynamics model, plasma model, and improved two-temperature model. But, each of these has its own limitations in special and temporal scales. For example, molecular dynamics combines the thermal and nonthermal phase transition mechanisms to explain material ablation due to lattice phase transition. However, some aspects have been described simply in this model, such as the alteration of the interaction force between atoms during the ablation process and approximate simplifications in the first-principles model, such as a time-dependent exchange-correlation, which influence the accuracy of theoretical predictions. The plasma model is used to describe photon absorption, plasma generation, and recombination of electronic systems before lattice phase transitions and offers a good explanation for the non-metallic ionization process. However, the phase transition process is not discussed in this model. Two-temperature model, described by Anisimov and colleagues for the interaction between ultrafast laser pulses and solids, is widely used for the prediction of the electron and phonon temperature distributions in laser processing. However, in this model, the electron density is set to a constant value; therefore, it is only applicable in metallic materials [3].

The models were extended by other researchers for more accurate calculations, such as the multiscale theoretical model and observation system, applicable for problems associated with each temporal scale to cover the overall scope of laser fabrication. The imaging system, such as sequentially time all-optical mapping photography, can be integrated with FSL fabrication system to realize real-time continuous observation and feedback of the fabrication process. Other theoretical models, based

### *Fundamentals of Femtosecond Laser and Its Application in Ophthalmology DOI: http://dx.doi.org/10.5772/intechopen.106701*

on simplified rate equations or a kinetic approach to Boltzmann's equations, have also been described. Models considered for the multiphoton non-linear optical process include two-photon absorption (which occurs when two photons are absorbed simultaneously by material) and two-photon polymerization (TPP; which occurs when two photons are absorbed on photosensitive material). This process changes the material and leads to polymerization by activating the photoinitiator-activated free radicals in the resist. Fabrication resolution of true 3D micro/nanostructures by TPP varies based on the laser energy, exposure duration, and concentration of the free radical [7].

Micro/nanostructures induced in transparent materials have been classified by Qiu et al. into four types based on optical coloration, refractive index modification, micro-hole creation, and micro-crack creation. FS pump-probe interferometry technique, with 100 fs temporal resolution, allows measuring the modification of refractive index induced by ultra-short intense laser pulses. When a dielectric material is subject to intense FSL, a large number of excited electrons may be generated by laser pulses, which produce intrinsic defects that make FSL an ideal tool for highprecision material processing. A complex secondary process of high-temperature and high-pressure plasma at the tightly focused laser point would induce a phase or structural modification of the material. The splitting and self-(de)focusing of FSL pulses inside dielectrics are the topics that researchers have used for the calculation of the excitation and relaxation channels of FS-induced carriers. Despite various models and explanations for laser-material interactions, the dynamics of specific phenomena are realized only partially. To quantify dynamics of laser-excited carriers, direct visualization of FSL dynamics using ultrafast imaging and spectral interferometry techniques has been designed and implemented successfully [8].