**Abstract**

Cheese whey (CW) is the yellow-green liquid main by-product from cheese manufacturing. Historically, it has been recognized as a major environmental pollutant. Nowadays, it represents a source of high-quality nutrients, such as lactose. Enzymatic bioprocesses, chemical synthetic reactions and microbial bioprocesses use lactose as substrate to obtain relevant derivatives such as lactitol, lactulose, lactosucrose, sialyllactose, kefiran and galacto-oligosaccharides. These lactose derivatives stimulate the growth of indigenous bifidobacteria and lactobacilli improving the intestinal motility, enhancing immunity and promoting the synthesis of vitamins. Also, they have versatile applications in pharmaceutical, biotechnological and food industries. Therefore, this book chapter shows the state of the art focusing on recent uses of CW lactose to produce value-added functional compounds and discusses new insights associated with their human health-promoting effects and well-being.

**Keywords:** cheese whey, bioprocesses, value-added functional compounds, lactose, kefiran

### **1. Introduction**

Cheese whey (CW) is the yellow-green liquid main by-product from the manufacture of cheese [1]. "Serum milk" remaining after the precipitation and removal of milk proteins by proteolytic enzymes or acid may also be defined as CW [2]. Industrial cheese manufacturing processes produce sweet or acid whey (**Figure 1**). Normally, the production of 1 kg of cheese requires 10 kg of milk originating 9 kg of CW [3, 4]. Worldwide cheese production was estimated by FAO (Food and Agricultural Organization) at 22.65 M tons in 2014 [5]. Therefore, CW is estimated at 203.9 M tons. Besides, the global growth rate of it is parallel to the cheese production and it has been calculated about 2% per annum [6]. This amount represents a challenge difficult to deal with.

Previous studies have reported high quantity of organic matter in CW [7]. The chemical composition of it is shown in **Table 1**. This by-product has 50, 000–102, 000 mg/L Chemical Oxygen Demand (COD) and 27, 000–60, 000 mg/L Biological

**Figure 1.**

*Overview of value-added functional compounds using lactose from cheese whey as substrate.*

**77**

**2.1 Lactitol**

*Value-Added Compounds with Health Benefits Produced from Cheese Whey Lactose*

Oxygen Demand (BOD) [7]. Due to its high BOD, CW presents 175-fold higher organic load than typical sewage effluents [6]. Lactose (4-*O*-ß-D-galactopyranosyl-D-glucose) is one of the main CW components. It causes about 90% of COD and BOD [8]. Moreover, CW represents about 85–95% of the milk volume. This amount has been partially land spreading, disposal to natural water bodies or municipal sewer systems [2–4]. Consequently, it is considered a major pollutant to the environment. On the other hand, CW is a liquid with high nutritional content [9]. It retains about 55% of the milk nutrients such as lactose, whey proteins, lipids, vitamins and minerals (**Table 1**). The chemical make-up of it can vary depending on the animal species from which milk was obtained [1]. It has been reported that about 50% of the total CW worldwide production is used it [10]. Animal feeding or as an ingredient in therapeutic formulations and food applications are common CW uses [11, 12]. Several technological approaches have been developed to transform it into value-added compounds reducing the environmental impact. CW processing is carried out directly by physical or thermal treatments to obtain protein isolate (WPI), whey protein concentrate (WPC), whey protein hydrolysates, whey permeate, lactose and other fractions. Indirectly, CW is used as substrate for enzymatic/ microbial bioprocesses to produce biogas, bioethanol, bioprotein, biopolymers, flavors and organic acids among others [11, 13]. Thus, it is an excellent substrate for physical treatments, enzymatic catalysis and metabolic microbial reactions that could be exploited by the medical, agri-food and biotechnology industries [6]. CW is a source of functional proteins, peptides, lipids and carbohydrates. This by-product is the main source of lactose manufactured on an industrial scale, as well as a low-cost substrate able to reduce high production costs. This disaccharide (C12H22O11) is the most abundant in CW representing around 70–72% (w/w) of the total solids [14]. The manufacture of edible lactose includes physical treatments such as ultrafiltration, nanofiltration, concentration, crystallization, washed and dried [15]. Lactose is a valuable ingredient used in a wide variety of products, such as bread, supplement in baby milk formulae, confectionaries and excipients for pharmaceutical products [16]. The use of lactose as raw material is a key point to several industrial and laboratory transformation processes. This disaccharide represents an ideal substrate to obtain relevant lactose derivatives associated with health-promoting benefits. For example, lactulose (C12H22O11; 4-*O*-ß-D-galactopyranosyl-ß- D-fructofuranose), which is synthetized by chemical isomerization, is a typical prebiotic as bifidus

Enzymatic catalytic and fermentation bioprocesses also use CW lactose as substrate to produce important value-added functional compounds [16, 17].

Lactitol is a lactose-derived compound defined as synthetic sugar alcohol (C12H24O11; 4-O-ß-D-galactopyranosyl-D-glucitol; molecular weight (MW),

Kefiran, organic acids, lactosucrose and galacto-oligosaccharides (GOS) are some of the most representative compounds able to improve human health and well-being (**Figure 1**). For instance, GOS [Gal-(Gal)n-Glu] that are produced by enzymatic polymerization using ß-galactosidase, improve gut health. Besides, exopolysaccharides such as kefiran are synthetized by the fermenting bioprocesses of lactic acid bacteria [16, 18]. Therefore, this chapter discusses recent uses of lactose from CW to produce value-added functional compounds. New insights associated with human

*DOI: http://dx.doi.org/10.5772/intechopen.94197*

factor added to infant formulae [16].

health benefits of these compounds are explored.

**2. Lactose derivatives with health benefits**

#### **Table 1.**

*Chemical composition of different types of cheese whey.*

#### *Value-Added Compounds with Health Benefits Produced from Cheese Whey Lactose DOI: http://dx.doi.org/10.5772/intechopen.94197*

Oxygen Demand (BOD) [7]. Due to its high BOD, CW presents 175-fold higher organic load than typical sewage effluents [6]. Lactose (4-*O*-ß-D-galactopyranosyl-D-glucose) is one of the main CW components. It causes about 90% of COD and BOD [8]. Moreover, CW represents about 85–95% of the milk volume. This amount has been partially land spreading, disposal to natural water bodies or municipal sewer systems [2–4]. Consequently, it is considered a major pollutant to the environment.

On the other hand, CW is a liquid with high nutritional content [9]. It retains about 55% of the milk nutrients such as lactose, whey proteins, lipids, vitamins and minerals (**Table 1**). The chemical make-up of it can vary depending on the animal species from which milk was obtained [1]. It has been reported that about 50% of the total CW worldwide production is used it [10]. Animal feeding or as an ingredient in therapeutic formulations and food applications are common CW uses [11, 12]. Several technological approaches have been developed to transform it into value-added compounds reducing the environmental impact. CW processing is carried out directly by physical or thermal treatments to obtain protein isolate (WPI), whey protein concentrate (WPC), whey protein hydrolysates, whey permeate, lactose and other fractions. Indirectly, CW is used as substrate for enzymatic/ microbial bioprocesses to produce biogas, bioethanol, bioprotein, biopolymers, flavors and organic acids among others [11, 13]. Thus, it is an excellent substrate for physical treatments, enzymatic catalysis and metabolic microbial reactions that could be exploited by the medical, agri-food and biotechnology industries [6].

CW is a source of functional proteins, peptides, lipids and carbohydrates. This by-product is the main source of lactose manufactured on an industrial scale, as well as a low-cost substrate able to reduce high production costs. This disaccharide (C12H22O11) is the most abundant in CW representing around 70–72% (w/w) of the total solids [14]. The manufacture of edible lactose includes physical treatments such as ultrafiltration, nanofiltration, concentration, crystallization, washed and dried [15]. Lactose is a valuable ingredient used in a wide variety of products, such as bread, supplement in baby milk formulae, confectionaries and excipients for pharmaceutical products [16].

The use of lactose as raw material is a key point to several industrial and laboratory transformation processes. This disaccharide represents an ideal substrate to obtain relevant lactose derivatives associated with health-promoting benefits. For example, lactulose (C12H22O11; 4-*O*-ß-D-galactopyranosyl-ß- D-fructofuranose), which is synthetized by chemical isomerization, is a typical prebiotic as bifidus factor added to infant formulae [16].

Enzymatic catalytic and fermentation bioprocesses also use CW lactose as substrate to produce important value-added functional compounds [16, 17]. Kefiran, organic acids, lactosucrose and galacto-oligosaccharides (GOS) are some of the most representative compounds able to improve human health and well-being (**Figure 1**). For instance, GOS [Gal-(Gal)n-Glu] that are produced by enzymatic polymerization using ß-galactosidase, improve gut health. Besides, exopolysaccharides such as kefiran are synthetized by the fermenting bioprocesses of lactic acid bacteria [16, 18]. Therefore, this chapter discusses recent uses of lactose from CW to produce value-added functional compounds. New insights associated with human health benefits of these compounds are explored.


Contents

Preface

Knowledge of cardiac arrhythmias has significantly improved in the last several decades. Although most cases are benign and easy to evaluate and treat, arrhythmias are sometimes challenging to differentiate, requiring quick recognition and response. The worst-case scenario is a hemodynamically unstable arrhythmia that may lead to heart failure or cardiac arrest that necessitates cardiopulmonary

A translational approach means implementing laboratory science into real-life clinical practice. Improvements in the science of arrhythmias have led to a decrease in morbidity and even mortality. Efforts to understand arrhythmic mechanisms have led to experimental modelling of arrhythmogenesis. These models are based on hypoxic-ischemic reperfusion myocardial insult, arrhythmogenic stimulating factors induced by electrolyte imbalance or administration of certain drugs. Over the last fifteen years, new methods of genetic testing have been developed that reveal new hereditary factors behind arrhythmias (e.g., cardiomyopathies), though

The key to the effective and appropriate treatment of clinical arrhythmias is the identification of etiology. The classical diagnosis is based on a thorough analysis of the patient's ECG. Causative therapy is driven by further clinical examination, laboratory testing of blood samples, imaging studies (e.g., echocardiography, CT and MRI scans), and invasive cardiac procedures. Patients suffering from arrhythmic cardiac arrest require immediate diagnostics and therapeutics regardless of setting

This book contains eight chapters in which the contributing authors highlight special aspects of the current scientific knowledge on cardiac arrhythmias.

The molecular background of catecholaminergic and calcium-dependent ventricular tachycardias is a point of interest since the latter may lead to sudden cardiac death. Genetic mutations in components of the calcium signaling pathway may induce dysregulation of calcium leading to overload, and this may be the pathway to target for therapy. Ryanodine receptors could be useful interventional gates to prevent

The COVID-19 pandemic has devastated daily medical and social life. Affecting mainly the respiratory tract and causing acute respiratory distress syndrome (ARDS), COVID infection has direct and indirect effects on the heart itself via secondary thrombogenicity, ischemia, myocarditis, and electrical inhomogeneity. The newly developed antiviral agents have potential proarrhythmic effects with or without the ischemic insult of the myocardial tissue. This proarrhythmic burden spurred scientists to begin using an endo-, mid myo-, and epicardial myocyte anisotropic preparation model for testing the safety of the first-used "anti-COVID" agent hydroxychloroquine. The latter acts electrophysiologically differently on myocardial cells in hypokalemic, COVID-associated ischemic, or overdosed

resuscitation and complex intensive care.

genetics-driven therapy is still lacking.

in order to increase their chances of survival.

catecholaminergic ventricular arrhythmias.

circumstances.


# **Isolation and Utilization of Essential Oils As Antimicrobials and Boosters of Antimicrobial Drug Activity**

Edited by Elwira Sieniawska, Greige-Gerges Helene and Adriana Trifan Printed Edition of the Special Issue Published in *Processes*

www.mdpi.com/journal/processes


**2. Biogenesis and function of miRNAs**

fications, making them important in the detection and treatment of multifactorial diseases

antagonist effects depending on whether or not they bind in the IRAP peptidase domain.

**Figure 1.** The renin-angiotensin system (RAS) and its components. This schematic depicts angiotensin ligands, receptors and the main enzymes involved; other peptidases and cathepsins also participate although to a lesser extent. All of the components of the RAS are present in the brain. RAS has two main axes: the pressor axis (tending towards an increase in blood pressure) comprising Ang II, ACE and AT1Rs and the counter-regulatory axis comprising Ang(1–7), ACE2 and MasR. Angiotensinogen is a substrate for renin to produce angiotensin I (Ang I), which is the inactive precursor of all angiotensin peptides. Conversion of Ang I to its most active ligand in the pressor axis, angiotensin II (Ang II), results from ACE-mediated hydrolysis [22]. Ang II is then sequentially converted to angiotensin III (Ang III) and angiotensin IV (Ang IV) by aminopeptidase A (APA) and aminopeptidase N (APN) respectively, which can be further cleaved by carboxypeptidase P (CP) and prolyl oligopeptidase (PO) to form angiotensin 3–7 (Ang3–7). Alternatively, Ang II can be converted, via the counter-regulatory axis to angiotensin 1–7 (Ang1–7) by carboxypeptidase P (CP) or ACE2, while both angiotensin A and Ang1–7 can be converted to alamandine by an ACE-mediated decarboxylation reaction [22–27]. Notably, angiotensin ligands acting on AT4R (also called insulin-regulated aminopeptidase (IRAP)) can have agonist or

Some of those epigenetic modifications are mediated by miRNAs, defined as single-stranded, non-coding RNA sequences approximately 21–23 nucleotides in length, expressed under physiological and pathological conditions [11, 12]. Deletion of complexes involved in miRNA biogenesis resulted in deleterious and non-viable phenotypes, highlighting their necessary involvement in the cellular development and differentiation [13, 14]. To date, 28,645 miRNAs have been reported in miRbase, a widely used resource for miRNA cataloging and nomenclature [15]. As epigenetic regulators of gene expression, functions of miRNAs include RNA degradation, inhibition of protein expression, regulation of methylation and histone modification on DNA [12, 14, 16]. miRNAs perform these functions by complementary base pairing

such as hypertension [7, 10].

174 Renin-Angiotensin System - Past, Present and Future

Canonical miRNA biogenesis starts with transcription of the primary miRNA sequence by RNA polymerase II and III [14]. Approximately half (52%) of human miRNAs are located in intergenic regions, 40% in intronic and 8% in exonic [28]. Intergenic miRNAs are independently expressed through promoter elements; yet related miRNAs that often have overlapping targets can be located on different chromosomes and expressed under different conditions. Intronic and exonic miRNAs that are clustered within 50 kilobases from each other show similar expression, while those spaced further apart tend not to [29]. However, there are some exceptions. Some miRNAs separated by more than 50 kilobases retain high correlation, likely as a result of co-expression [30]. The differential localization and expression of miRNAs suggest an evolutionary response to environmental insults and specific cell responses, a theory supported by observed higher numbers of miRNAs expressed in organisms of higher complexity [31–33].

**Figure 2A–F** summarizes the process of miRNA biogenesis. Primary miRNAs are cleaved in the nucleus by a nuclear microprocessor complex comprised of the RNase III endoribonuclease DROSHA and its double-stranded RNA-binding protein DGCR8—DiGeorge Critical

**Figure 2.** MicroRNA biogenesis and function. (A) Primary miRNAs are cleaved in the nucleus by the RNase III endoribonuclease DROSHA and DGCR8. (B) Once the primary miRNA is cleaved, the nuclear transport receptor exportin 5 binds the 3′ overhang structure of the pre-miRNA to export it to the cytoplasm. (C) The RNase III enzyme Dicer and TRBP and PACT target the pre-miRNA through the 3′ overhang, converting it into mature miRNA, liberating a duplex nucleotide structure with two nucleotides protruding at the 3′ end. (D) The guide strand is loaded into the RNAinduced silencing complex (RISC), and the passenger strand is degraded by RNases. (E) Complementary pairing with the seed region to mRNAs determines target binding and guides argonaute proteins to stop translation. Accumulation of untranslated mRNA in the cytoplasm allows recruitment of members of the GW182 protein family. (F) Deadenylase complexes cause destabilization of the transcript and further degradation by RNase activity.

Region 8, **Figure 2A** [34]. This cleavage by DROSHA/DGCR8 produces a 60 nucleotide stemloop structure with a 3′ overhang, the pre-miRNA [11, 34, 35]. The primary miRNA can also be further subjected to RNA editing by ADARs (adenosine deaminases acting on RNA) that modify adenosine to inosine producing miRNA isoforms called isomiRs [36].

Exportin 5 allows export of the pre-miRNA to the cytoplasm, **Figure 2B** [36], where Dicer and substrate stabilizing binding partners, TRBP (trans-activation response RNA-binding protein) and PACT (protein activator of RNA-activated protein kinase) facilitate conversion into mature miRNA, **Figure 2C** [12, 14]. Two strands result from the unwinding of the duplex, the guide (3p) and passenger (5p) strands. Most of miRNA effects are mediated by the 3′ form; the 5′ form comprises <10% of all miRNA reads in humans [36]. The guide strand is loaded into the RNA-induced silencing complex (RISC) and the passenger strand is degraded by RNases, **Figure 2D**. IsomiRs can also be produced at this step by trimming and capping of the mature miRNA.

Non-canonical miRNA biogenesis is independent of DROSHA/DGCR8 processing in the nucleus. Such biogenesis arises if an intron is spliced lacking the sequences ordinarily flanking the stem region of a primary miRNA and it is of sufficient size to generate a pre-miRNA and it can be exported to the cytoplasm and further processed as a pre-miRNA to form a mirtron. Alongside mirtrons, other RNA sequences derived from transfer RNA and small nucleolar RNA are loaded into an RISC complex and act as miRNAs [13, 14, 29].

The RISC is a ribonucleoprotein complex that mediates mRNA degradation, destabilization or translational inhibition, whatever the biogenesis mechanism and comprises the miRNA guide strand and argonaute proteins, **Figure 2E**. The complementary base pairing of the miRNA seed region (2nd to 8th position on the 5′ end) to mRNAs determines target binding and guides argonaute proteins [28, 37, 38]. miRNA levels are dependent on argonaute proteins [39, 40] that are also present in the nucleus and currently, only miRNA-29b has been shown to translocate and localize in the nucleus [14, 39, 41]. In humans, argonaute 2 (also called eukaryotic translation initiation factor 2C) cleaves target mRNAs [29] but can also block other translation initiator factors and ribosomal subunits [42].

After pairing of the miRNA seed region, protein translation can be inhibited, **Figure 2E**. Accumulation of untranslated mRNA in the cytoplasm allows argonaute 2 to recruit members of the GW182 protein family, which are enriched in cytoplasmic areas called processing bodies (p-bodies) [42]. Here, the mRNA is destabilized by deadenylase complexes and further degraded by RNases [43–45]. Finally, the effect miRNAs have on protein or mRNA levels depends on the position where the miRNA binds and five different classes of miRNA binding have been determined [12, 46, 47]. Most miRNA effects are mediated by binding at the 3′ UTR of mRNA and further processing as described previously, non-canonical binding sites represent <1% [48].


**1. Introduction**

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in the Caucasian population [1]. It comprises a heterogeneous group of diseases whose common characteristic is the inability to produce antibodies due to a defect in the development or function of B lymphocytes. The age of onset is very heterogeneous, ranging from childhood to the second and third decade of life [2]. Clinical and immunological manifestations vary between affected individuals, but the principal manifestations of CVID are increased susceptibility to recurrent infections, mainly of the respiratory tract, hypogammaglobulinemia, and low antibody response to vaccine antigens, which cannot be explained by previous exposures, treatments, or infections. In addition,

**Citation:** Díaz-Alberola, I.; Espuch-Oliver, A.; García-Aznar, J.M.; Ganoza-Gallardo, C.;

Aguilera-Franco, M.; Sampedro, A.; Jiménez, P.; López-Nevot, M.Á. Common Variable Immunodeficiency Associated with a De Novo *IKZF1* Variant and a Low Humoral Immune Response to the SARS-CoV-2 Vaccine. *J. Clin. Med.* **2022**, *11*, 2303. https:// doi.org/10.3390/jcm11092303

Academic Editor: Rita Consolini

Received: 30 March 2022 Accepted: 18 April 2022 Published: 20 April 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/).

some patients also have autoimmune diseases, alteration in lymphocyte populations, or cancer [3].

Currently, its diagnosis is complicated by the lack of standardized diagnostic criteria due to its great clinical and analytical heterogeneity, low awareness on the part of clinicians, and the similarity of the disease with other immune disorders. Even so, several guidelines have emerged that help in the diagnosis of CVID, including the International Consensus Document (ICON) guidelines from 2015 [4] and the European Society for Immunodeficiencies (ESID) Registry Working Definitions for the Clinical Diagnosis of Inborn Errors of Immunity from 2019, with several updates [5]. In the laboratory, determinations of serum levels of immunoglobulin (Ig)G, IgA, and IgM antibodies, the study of lymphocyte populations, and B-cell immunophenotyping are useful in evaluating the patient's condition [2].

It is well known that CVID patients present suboptimal responses to vaccines, some of them being potentially dangerous and even contraindicated (such as live vaccines). In fact, the current ESID guideline for CVID includes a poor antibody response to vaccines as a criterion [5], although several studies show that the response to vaccines is not uniform in patients with mild hypogammaglobulinemia [6]. Very few studies exist on humoral and cellular responses to COVID-19 vaccines in patients with CVID [7–9]. This is due, on the one hand, to the fact that SARS-CoV-2 infection is very recent and, on the other hand, because the response to immunization depends on the type of vaccine, the patient's immune defect, and the type of antigen studied [7]. Looking at the humoral and cellular response to other vaccines not related to SARS-CoV-2 in patients with CVID, we find studies that suggest that these patients have a lower humoral response to the vaccines compared to the control group while maintaining a good cellular response [10,11].

Regarding the etiology, most cases of CVID are idiopathic, but to date, between 10 and 35% of CVID patients present monogenic defects, predominantly autosomal dominant with incomplete penetrance or with late onset of symptoms. The development of highthroughput sequencing technologies has allowed the identification of several mutations in genes encoding proteins essential for immune function that could be involved in the development of CVID. Thus, panels of primary immunodeficiency-associated genes have been created, allowing rapid screening of identified mutations using genetic techniques. Some of the CVID-associated genes include: *ICOS* (OMIM: #604558), *CD19* (OMIM: #107265), *CD81* (OMIM: #186845), *MS4A1* (OMIM: #112210), *CR2* (OMIM: #120650), *TNFSF12* (OMIM: #602695), *CTLA4* (OMIM: #123890), *LRBA* (OMIM: #606453) *TNFRSF13B* (OMIM: #60907), *TNFRSF13C* (OMIM#606269), *NFKB1* (OMIM: #164011), *NFKB2* (OMIM: #164012), *IL21* (OMIM: #605384), *IRF2BP2* (OMIM: #615332), *PIK3CD* (OMIM: #602839), *STAT3* (OMIM: #102582), and others [3]. Alteration in any of these genes can cause perturbations of specific immune pathways, resulting in "unique phenotypes" that can aid in the diagnosis of CVID [2]. In fact, in the 2019 update of the classification of primary immunodeficiencies (PID) by the expert committee of the International Union of Immunological Societies (IUIS), CVID is included within the group of PID with a predominance of antibody deficiencies. Furthermore, information regarding clinical, analytical, and molecular tests is provided and that could help clinicians in the diagnosis and management of these patients and their relatives [12].

Here, we report a case of a 46-year-old patient diagnosed with CVID in current treatment with intravenous immunoglobulins and clinically stable. Because of his negative family history of primary immunodeficiencies and in the context of the SARS-CoV-2 pandemic, we reassessed the patient immunologically, employing an NGS analysis to try to clarify the genetic cause of his disease, and analyzed his serological and cellular response to the COVID-19 vaccine. We identified a heterozygous R162Q variant of the *IKZF1* gene in our patient that was not present in his parents. This variant was previously described as pathogenic, associated with CVID type 13 following an autosomal dominant inheritance and high penetrance. Therefore, we present for the first time a case of CVID associated with a de novo heterozygous R162Q variant in the *IKZF1* gene in a patient with a low antibody immune response and a positive cellular response to the complete COVID-19 vaccination program.


*Edited by Bimal Kumar Ghimire*

This book integrates knowledge of plant biotechnology, plant physiology, and the environment. It presents new information about soil organic carbon sequestration using plant species (tropical grasses) that have potential in climate change mitigation. It also presents scientific knowledge on the multipurpose role of microRNA (miRNA), focusing mainly on stress tolerance in crop plants. Chapters discuss uses, methods, and advantages of recombinant DNA technology and novel plant biotechnology applications for plant-based vaccines. This volume brings together knowledge about non-edible plants seeds as potential sources of biodiesel production to mitigate the global energy crisis.

ISBN 978-1-83969-258-1

Botany - Recent Advances and Applications

Published in London, UK © 2021 IntechOpen © Samuel-Elias / Unsplash


**5. Conclusion**

Remarkable progress has been made in elucidating the effects of estrogens on the vascular system, and the cellular and molecular mechanisms by which those effects are achieved. The analysis of published data supports estradiol increases prostacyclin vascular production in accordance with experimental and clinical research. This effect seems to be mediated mainly through ERα-dependent pathways which involve an increase in COX-1 and, in some cases, COX-2 activation and/or expression, and an augment in prostacyclin synthase expression, without affecting thromboxane A2 production. As a consequence, estradiol may reduce vascular tone and improve endothelium-dependent vasodilation (Figure 2).


**7. Essential healthcare services to attaining cost-effective health management of farm animals**

Prevention and control of pests and diseases of farm animals are essential to achieving profitable and sustainable farm animal production. This involves putting up all necessary actions to ensure that animals in stock are free of infections or debilitating effects of pests and diseases. Such actions are not only to save the animals but also give an added opportunity of eliminating or reducing the cost of treatment, which is usually expensive where animals were to be treated. However, an important step to preventing and controlling disease outbreak in farm animals by farmers is cognition of health communication behaviours of the farm animals, nature and virulence pathogenic organisms that may induce ailment, and signs that are disease-laden and symptoms of emerging diseases in the animals. Because of this, farmers may have to promptly and diligently take the following actions for good health management3 of farm animals and as well ensure profitable and sustainable livestock production.

**39**

**Figure 4.**

*A lamb with lame foot as result of infection. Source: Photo by author.*

*Farm Animals' Health Behaviours: An Essential Communicative Signal for Farmers' Veterinary…*

Effective care of farm animals begins with a vigil on the posture and environment of the animals. This entails regular checks on kept animals in stalls and fields and intermittent physical examination of the animals' bodies for early detection of impairment of their normal behaviours and any possible ill-health. Given this, farmers must be on the lookout for signs and conditions that may engender disease outbreak or infestation of pests in their animals. Hence, the understanding that a healthy animal will normally be on the stand on sighting their attendants and/or move excitedly when being approached to be fed makes it possible for a farmer to know that failure or refusal of an animal to stand up or move is a sign of impairment of the normal health of the animals and as such would need to be attended to, at least for examination and determination of what the health issue might be. Field experience in this regard with a livestock attendant 0n small ruminant farms shows that regular checks on the animals daily made it possible for quick detection of impairment of the animals' normal health condition. Observed cases of health issues in the stock as a result of regular checks on the animals include lameness (**Figure 4**) and refusal of one or two of the animals to move on being an approach. With these signs, cases of foot rot or scald, pneumonia, infestation by sheep fleas and worms in the animals. Physical examination of bodies of the animals for insects or pests is equally of great value in early detection of flies' infestation in ruminant skin and lice in poultry birds. Surveillance though begins with individual farmers and their farms, collective efforts become crucial to curtailing the spread of infectious diseases from farm to farm. Surveillance is about disease identification and reporting cases of infections by livestock keepers to animals' health agencies and veterinarians to enable disease patterns to be monitored [79]. On this note, the World Organisation of Animal Health—OIE, emphasises that effective surveillance system entails identification and/or observation of emerging disease and reporting such for sample and data collection, epidemiological and laboratory investigations, and management and communication of the resulting information to provide guidance on priorities and targets for the application of interventions to effectively

Hygiene practice is an important aspect of animals' health management and this entails keeping the farm environment free of any anything or condition that could induce pest infestation and disease infections in the animals. This includes

*DOI: http://dx.doi.org/10.5772/intechopen.89738*

**7.1 Surveillance**

control of the disease [80].

**7.2 Hygiene practice**

2 Not all diseases in farm animals could be determined by physical examination. It may require clinical examination, immune system function, nociceptor response and behavioural assessment for accurate diagnosis of a particular disease which of course could not be done a farmer but by a veterinarian.

3 This section and of course this chapter did not provide information on treatment, prevention, and control of specific diseases but on basic actions that could be taken in health management bused on animal attendants' cognition of the animals' vocalisation and the observed visual cue for health management of the animals.

*Farm Animals' Health Behaviours: An Essential Communicative Signal for Farmers' Veterinary… DOI: http://dx.doi.org/10.5772/intechopen.89738*

## **7.1 Surveillance**

*Livestock Health and Farming*

to emerge or already discomforting the animals2

their animals for quick detection of laden diseases in their stock.

**management of farm animals**

**7. Essential healthcare services to attaining cost-effective health**

Prevention and control of pests and diseases of farm animals are essential to achieving profitable and sustainable farm animal production. This involves putting up all necessary actions to ensure that animals in stock are free of infections or debilitating effects of pests and diseases. Such actions are not only to save the animals but also give an added opportunity of eliminating or reducing the cost of treatment, which is usually expensive where animals were to be treated. However, an important step to preventing and controlling disease outbreak in farm animals by farmers is cognition of health communication behaviours of the farm animals, nature and virulence pathogenic organisms that may induce ailment, and signs that are disease-laden and symptoms of emerging diseases in the animals. Because of this, farmers may have to promptly and diligently take the following actions for good health management3

farm animals and as well ensure profitable and sustainable livestock production.

2 Not all diseases in farm animals could be determined by physical examination. It may require clinical examination, immune system function, nociceptor response and behavioural assessment for accurate diagnosis of a particular disease which of course could not be done a farmer but by a veterinarian. 3 This section and of course this chapter did not provide information on treatment, prevention, and control of specific diseases but on basic actions that could be taken in health management bused on animal attendants' cognition of the animals' vocalisation and the observed visual cue for health management of

Body movement of the animals is also essential cues to understanding the health communication behaviours of the animals. For instance, cattle will normally have their tails raised and positioned horizontally when defecating or urinating bur observation such positioning of tail aside the need for excretion is an indication of the health issue to be given attention. Also, kicking and tail swishing may be performed in response to acute pain with these signals directed toward the painful stimulus [49]. The ability of farmers to understand the communicative signals, however, depends on their good knowledge of different animal diseases and the signs that may be shown before the emergence of a particular disease. Based on experience, some farmers have developed the skills and intuition to rightly interpret behavioural signals of an animal about a specific kind of illness that is most likely

of goats' communicate their owner that their pen is heavily infested by lice was by their reluctance to enter the pen each day they return from free-range, and when forced into the pen, they began an unusual and constant stamping of their feet. But a curious examination of the sudden reluctance of entry into the pen revealed that the dusty floor of the pen was highly infested by lice which always walk into the goats' underneath hair thereby causing skin irritation to the animals. This was discovered when a multitude of lice flung onto the farmer's legs on entering pen thereby necessitating thorough cleaning of the pen and thereafter, no constant stamping of feet was observed among the goat. In essence, every behavioural actions farm animals might mean a lot and as such, livestock farmers need to understand and be able to distinguish between normal and abnormal behaviours of their farm animals to ensure good management of the animals' welfare. But farmers who do not have the experience or skill to accurately interpret the observed health communication behaviour of a farm animal would have to consult the service of a veterinarian. Thus farmers would have to consciously monitor the social actions of

. A field experience by which a set

of

**38**

the animals.

Effective care of farm animals begins with a vigil on the posture and environment of the animals. This entails regular checks on kept animals in stalls and fields and intermittent physical examination of the animals' bodies for early detection of impairment of their normal behaviours and any possible ill-health. Given this, farmers must be on the lookout for signs and conditions that may engender disease outbreak or infestation of pests in their animals. Hence, the understanding that a healthy animal will normally be on the stand on sighting their attendants and/or move excitedly when being approached to be fed makes it possible for a farmer to know that failure or refusal of an animal to stand up or move is a sign of impairment of the normal health of the animals and as such would need to be attended to, at least for examination and determination of what the health issue might be. Field experience in this regard with a livestock attendant 0n small ruminant farms shows that regular checks on the animals daily made it possible for quick detection of impairment of the animals' normal health condition. Observed cases of health issues in the stock as a result of regular checks on the animals include lameness (**Figure 4**) and refusal of one or two of the animals to move on being an approach. With these signs, cases of foot rot or scald, pneumonia, infestation by sheep fleas and worms in the animals. Physical examination of bodies of the animals for insects or pests is equally of great value in early detection of flies' infestation in ruminant skin and lice in poultry birds. Surveillance though begins with individual farmers and their farms, collective efforts become crucial to curtailing the spread of infectious diseases from farm to farm. Surveillance is about disease identification and reporting cases of infections by livestock keepers to animals' health agencies and veterinarians to enable disease patterns to be monitored [79]. On this note, the World Organisation of Animal Health—OIE, emphasises that effective surveillance system entails identification and/or observation of emerging disease and reporting such for sample and data collection, epidemiological and laboratory investigations, and management and communication of the resulting information to provide guidance on priorities and targets for the application of interventions to effectively control of the disease [80].


**1. Introduction**

242 Thermoplastic Elastomers

Yan, C., Nakao, M., Go, T., Matsumoto, K. & Hatamura, Y. (2003). "Injection molding for

Yang, R., Jiang, J., Meng, W. J. & Wang, W. (2006). "Numerical simulation and fabrication of

Yang, Z., Dong, B., Huang, Y., Liu, L., Yan, F.-Y., & Lo, H.-L. (2005). "Enhanced wear

Yao, D., Kimerling, T & Kim, B. (2006). "High-frequency proximity heating for injection

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*Technologies* 9(3), 188-191.

545-553.

84(24), 5552-5555.

microstructures controlling mold-core extrusion and cavity heat-flux." *Microsystem*

microscale, multilevel, tapered mold inserts using UV-Lithographie, Galvanoformung, Abformung (LIGA) technology." *Microsystem Technologies* 12(6),

resistance and micro-hardness of polystyrene nanocomposites by carbon

Wall Carbon Nanotubes and their Mechanical Properties." *Physical Review Letters*

reinforced polyurethane foam: Processing, characterization and modelling of

Nonwovens are a unique class of textile materials, formed by bonding the fibers by various techniques. The demand through the nonwovens is increasing on the world day by day and nonwovens are getting integrated to more application areas rapidly. Today, nonwovens have achieved an excellent position among the products of daily use like hygiene, medicine, household and more. (Ebeling et al., 2006)

Meltblown nonwovens are a relatively new class of thermoplastic based nonwoven materials which integrate to new application areas to replace conventional textile materials. Due to their unique micro structure, low porosity, absorbency, light weight and high surface area, microfiber meltblown nonwovens are promising materials of the future. Meltblowing is a one step process which enables to produce microfiber nonwovens directly from thermoplastic polymers with the aid of high velocity air to attenuate the melt filaments. In this process high velocity air blows a molten thermoplastic resin from an extruder die tip onto a conveyor or take up screen to form a fine fiberous and selfbonding web. (Bang One Lee et al., 2010) It has become an important industrial technique in nonwovens because of its ability to produce fabrics of microfiber structure suitable for filtration media, thermal insulators, battery seperators, oil absorbents, wipes, apparel, medical applications and many lamination applications. (Zhang et al., 2002 , Duran&Perincek, 2010; Dutton, 2008)

Meltblowing is a unique process since it is used almost exclusively to produce microfibers rather than fibers the size of conventional textile fibers. Meltblown microfibers generally have diameters in the range of 2 to 4 µm, although they may be as small as 0.1 µm and as large as 10 to 15 µm. Differences between meltblown nonwoven fabrics and other nonwoven fabrics, such as degree of softness, cover or opacity, and porosity can generally be traced to differences in filament size. (Bang One Lee et al., 2010)

Meltblowing technology is used for producing light fiber webs directly from polymers. This process process allows the production of ultrafine filament nonwovens under very economical conditions. In the basic melt blowing process, a thermoplastic fibre forming polymer is melted in an extruder, pumped through die holes and then the melt enters high-

Investigation of the Production Parameters and

fibers occurs. (Dahiya et al., 2004)

form fine fibers.

Physical Characteristics of Polypropylene Meltblown Nonwovens 245

from these holes to form filament strands which are subsequently attenuated by hot air to

As soon as the molten polymer is extruded from the die holes, high velocity hot air streams blown from the top and bottom sides of the die nosepiece, attenuate the polymer streams to form microfibers. As the hot air stream containing the microfibers progresses toward the collector screen, it draws in a large amount of surrounding air that cools and solidifies the fibers. The solidified fibers subsequently get laid randomly onto the collecting screen, forming a self-bonded nonwoven web. (Duran&Perincek,2010; Dutton, 2008; Dahiya et al., 2004) Usually, a vacuum is applied to the inside of the collector screen to withdraw the hot air and enhance the fiber laying process. The combination of fiber entanglement and fiberto-fiber bonding generally produce enough web cohesion so that the web can be readily used without further bonding. However, additional bonding and finishing processes may

The properties of the meltblown webs are affected by various production parameters including air temperature, polymer/die temperature, die to collector distance (DCD), collector speed, polymer throughput, air throughput, die hole size and air angle. All of these affect the final properties of the nonwoven web. Both polymer throughput and air flow rate control the final fiber diameter, fiber entanglement, basis weight and the attenuating zone. Polymer/die and air temperatures combined with air flow rate affect the uniformity, shot formation which can be described as large globules of nonfibrous polymer larger in diameter than fibers in webs, rope and fly formation, fabric appearance and touch. (Dahiya et al., 2004) Because meltblowing uses an attenuating air stream to draw and orient the fibres, the distance between the polymer orifice and the collection surface includes the fiber characteristics and resulting fabric properties. This distance is commonly referred to as the die-to-collector distance (DCD). The period of time that fibres spend in flight before being collected influences fiber orientation, strength and surface properties. A varying DCD permits the production of structures with varying properties from stiff and brittle at close distance to soft and bulky at large distance.  Air angle controls the nature of air flow, i.e. as the air angle approaches 90 it results in a high degree of fiber separation or turbulence that leads to random fiber distribution. At an angle of 30, roped or parallel fibers deposited as loosely coiled bundles of fibers are generated. This structure is undesirable. At angles greater than 30, attenuation as well as breakage of

The melt blowing process is amenable to a wide range of polymers in terms of viscosities and blends. The type of polymer or resin used defines the elasticity, softness, wetability, dyeability, chemical resistance and other related properties of formed webs. Some polymers, which can be used for the formation of melt-blown webs are listed as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA) and polylacticacid (PLA). Polypropylene (PP) is the most widely used polymer for meltblowing process, because it has a low viscosity, a low melting point and is easy to draw into fibers. A lot of efforts have been made in the last 30 years on the process study, new resin and product

development and process improvements. (Zhang et al., 2002; Dahiya et al., 2004)

further be applied to these melt-blown webs. (Dahiya et al., 2004)

speed, hot air streams. Streams of hot air exiting from the left and right sides of the die nosepiece rapidly attenuate the extruded polymer streams to form extremely fine filaments. The filaments then are blown by high-velocity air onto a collector screen, thus forming a fine-filtered, self-bonded nonwoven web. After that, they are bonded and wound to form roll goods for further processing. Web structure begins to develop when fiber entanglement first occurs, but network structure becomes fixed only when fibers contact the collector and their motion ceases. (Duran&Perincek, 2010; Randall et al, 2004; Rupp, 2008)

Because the meltblowing process employs high velocity air to impinge upon the polymer as it exits the orifices, it elongates the polymer strands from 500 m diameter to diameters as small as 0.1 m. Extreme entanglemet of fibres, characterizing meltblown fibrous webs, produces coherent fiber webs. Unique micrometer characteristics of meltblown structures produce a high surface area per unit weight and fine porosity. Therefore meltblown technology can be used to produce efficient filter materials that are able to filter particles as small as 0.5 m. (Farer et al., 2003)

The melt blown process generally consists of five major components, which are the extruder, metering pump, die assembly, web formation, and winding. The extruder, which consists of a heated barrel with a rotating screw inside is one of the important elements in all polymer processing. In the extruder, the polymer pellets or granules are heated and melted until appropriate temperature and viscosity are reached. The extruder is divided in to three different zones. (Dahiya et al., 2004) The feed zone, is the zone where the polymer pellets are preheated and pushed to the next zone. The transition zone has a decreasing depth channel in order to compress and homogenize the melted polymer. The melting of the pellets in the extruder is due to the heat and friction of the viscous flow and the mechanical action between the screw and the walls of the barrel. The molten polymer is then fed to the metering pump to ensure uniform polymer feed to the die assembly. (Duran&Perincek,2010; Dutton, 2008; Dahiya et al., 2004) The metering zone is the last zone in the extruder whose main purpose is to generate maximum pressure in order to pump the molten polymer in the forward direction. (Dahiya et al., 2004) The metering pump is a device for uniform melt delivery to the die assembly. It ensures consistent flow of clean polymer mix under process variations in viscosity, pressure, and temperature. The metering pump also provides polymer metering and the required process pressure. At this point the breaker plate controls the pressure generated with a screen pack placed near to the screw discharge. The breaker plate also filters out any impurities such as dirt, foreign particle metal particles and melted polymer lumps. (Dahiya et al., 2004)

The die assembly is the most important element of the melt blown process. It has three distinct components: polymer-feed distribution, die nosepiece, and air manifolds. The feed distribution is usually designed in such a way that the polymer distribution is less dependent on the shear properties of the polymer. This feature allows the melt blowing of widely different polymeric materials with one distribution system. The feed distribution balances both the flow and the residence time across the width of the die. From the feed distribution channel the polymer melt goes directly to the die nosepiece. The web uniformity hinges largely on the design and fabrication of the nosepiece. Therefore, the die nosepiece in the melt blowing process requires very tight tolerances, which have made their fabrication very costly.  The polymer melt is extruded

speed, hot air streams. Streams of hot air exiting from the left and right sides of the die nosepiece rapidly attenuate the extruded polymer streams to form extremely fine filaments. The filaments then are blown by high-velocity air onto a collector screen, thus forming a fine-filtered, self-bonded nonwoven web. After that, they are bonded and wound to form roll goods for further processing. Web structure begins to develop when fiber entanglement first occurs, but network structure becomes fixed only when fibers contact the collector and

Because the meltblowing process employs high velocity air to impinge upon the polymer as it exits the orifices, it elongates the polymer strands from 500 m diameter to diameters as small as 0.1 m. Extreme entanglemet of fibres, characterizing meltblown fibrous webs, produces coherent fiber webs. Unique micrometer characteristics of meltblown structures produce a high surface area per unit weight and fine porosity. Therefore meltblown technology can be used to produce efficient filter materials that are able to filter particles as

The melt blown process generally consists of five major components, which are the extruder, metering pump, die assembly, web formation, and winding. The extruder, which consists of a heated barrel with a rotating screw inside is one of the important elements in all polymer processing. In the extruder, the polymer pellets or granules are heated and melted until appropriate temperature and viscosity are reached. The extruder is divided in to three different zones. (Dahiya et al., 2004) The feed zone, is the zone where the polymer pellets are preheated and pushed to the next zone. The transition zone has a decreasing depth channel in order to compress and homogenize the melted polymer. The melting of the pellets in the extruder is due to the heat and friction of the viscous flow and the mechanical action between the screw and the walls of the barrel. The molten polymer is then fed to the metering pump to ensure uniform polymer feed to the die assembly. (Duran&Perincek,2010; Dutton, 2008; Dahiya et al., 2004) The metering zone is the last zone in the extruder whose main purpose is to generate maximum pressure in order to pump the molten polymer in the forward direction. (Dahiya et al., 2004) The metering pump is a device for uniform melt delivery to the die assembly. It ensures consistent flow of clean polymer mix under process variations in viscosity, pressure, and temperature. The metering pump also provides polymer metering and the required process pressure. At this point the breaker plate controls the pressure generated with a screen pack placed near to the screw discharge. The breaker plate also filters out any impurities such as dirt, foreign particle metal particles and melted

The die assembly is the most important element of the melt blown process. It has three distinct components: polymer-feed distribution, die nosepiece, and air manifolds. The feed distribution is usually designed in such a way that the polymer distribution is less dependent on the shear properties of the polymer. This feature allows the melt blowing of widely different polymeric materials with one distribution system. The feed distribution balances both the flow and the residence time across the width of the die. From the feed distribution channel the polymer melt goes directly to the die nosepiece. The web uniformity hinges largely on the design and fabrication of the nosepiece. Therefore, the die nosepiece in the melt blowing process requires very tight tolerances, which have made their fabrication very costly.  The polymer melt is extruded

their motion ceases. (Duran&Perincek, 2010; Randall et al, 2004; Rupp, 2008)

small as 0.5 m. (Farer et al., 2003)

polymer lumps. (Dahiya et al., 2004)

from these holes to form filament strands which are subsequently attenuated by hot air to form fine fibers.

As soon as the molten polymer is extruded from the die holes, high velocity hot air streams blown from the top and bottom sides of the die nosepiece, attenuate the polymer streams to form microfibers. As the hot air stream containing the microfibers progresses toward the collector screen, it draws in a large amount of surrounding air that cools and solidifies the fibers. The solidified fibers subsequently get laid randomly onto the collecting screen, forming a self-bonded nonwoven web. (Duran&Perincek,2010; Dutton, 2008; Dahiya et al., 2004) Usually, a vacuum is applied to the inside of the collector screen to withdraw the hot air and enhance the fiber laying process. The combination of fiber entanglement and fiberto-fiber bonding generally produce enough web cohesion so that the web can be readily used without further bonding. However, additional bonding and finishing processes may further be applied to these melt-blown webs.  All of these affect the final properties of the nonwoven web. Both polymer throughput and air flow rate control the final fiber diameter, fiber entanglement, basis weight and the attenuating zone. Polymer/die and air temperatures combined with air flow rate affect the uniformity, shot formation which can be described as large globules of nonfibrous polymer larger in diameter than fibers in webs, rope and fly formation, fabric appearance and touch. (Dahiya et al., 2004) Because meltblowing uses an attenuating air stream to draw and orient the fibres, the distance between the polymer orifice and the collection surface includes the fiber characteristics and resulting fabric properties. This distance is commonly referred to as the die-to-collector distance (DCD). The period of time that fibres spend in flight before being collected influences fiber orientation, strength and surface properties. A varying DCD permits the production of structures with varying properties from stiff and brittle at close distance to soft and bulky at large distance.  Air angle controls the nature of air flow, i.e. as the air angle approaches 90 it results in a high degree of fiber separation or turbulence that leads to random fiber distribution. At an angle of 30, roped or parallel fibers deposited as loosely coiled bundles of fibers are generated. This structure is undesirable. At angles greater than 30, attenuation as well as breakage of fibers occurs. (Dahiya et al., 2004)

The melt blowing process is amenable to a wide range of polymers in terms of viscosities and blends. The type of polymer or resin used defines the elasticity, softness, wetability, dyeability, chemical resistance and other related properties of formed webs. Some polymers, which can be used for the formation of melt-blown webs are listed as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA) and polylacticacid (PLA). Polypropylene (PP) is the most widely used polymer for meltblowing process, because it has a low viscosity, a low melting point and is easy to draw into fibers. A lot of efforts have been made in the last 30 years on the process study, new resin and product development and process improvements. (Zhang et al., 2002; Dahiya et al., 2004)

Investigation of the Production Parameters and

**2. Material and method**

in this study can be seen in Table 2.

diameter and tensile properties.

Physical Characteristics of Polypropylene Meltblown Nonwovens 247

Beside many advantages they provide, meltblowns have limited strength characteristics and poor abrasion resistance. (Farer et al., 2003) Therefore, they often are combined with other nonwovens. Spunbonds and other types of nonwovens also can be covered and refined with meltblowns. Today it is possible to implement production lines not only with spunbonds, but also with a meltblown component, to produce different types of nonwovens with an even more of a textile feeling. Approximately 40 percent of meltblowns are manufactured using a stand-alone process. The remaining meltblowns are combined with spunbonds or laminated to form other materials. Combinations with spunbonded fabrics are primarily used to make nonwoven materials with barrier properties. Another variation is the combination of meltblown with cellulose or an absorbent powder to produce a soft, strong, but still absorbent material that can retain absorbed liquid while still keeping its strength. The outcome is a combination of spunbonds (S) and meltblowns (M), resulting in SMS, or even SSMMMSS or other combinations, depending on the final product. So many different products can be manufactured and implemented from SMS to SSMMMSS. Some examples of their applications are hygiene, baby and adult diapers, medical products, protective masks for medical use, general use as a barrier layers, paper composites, work safety, protective clothing, breathing masks and combination with other nonwovens. (Rupp, 2008)

In this chapter, the results of a study about polypropylene microfibre meltblown nonwovens were covered. Aspects related to the production phase, properties of the materials produced and application areas were discussed. In the content of this study, effect of some production parameters namely die air pressure, collector drum speed, collector vacuum and extruder pressure on the physical properties of the web structure such as thickness, basis weight, air permeability, tensile properties, surface friction and fiber diameter were investigated.

As raw material, PP with 1100 melt flow rate (MFR), 0.75 g/cm3 density and 335 F melting point was used. The main production settings namely; extruder temperatures, die temperature, air temperature (the air fed to the spinerette to spin the fibers), die hole

> **Production Setting Value**  Extruder zone 1 temperature (°F) 270 Extruder zone 2 temperature (°F) 320 Extruder zone 3 temperature (°F) 370 Die temperature (°F) 336 Air temperature (°F) 350 Die hole diameter (inches) 0.09 Die-to collector distance (cm) 50

The sample codes and production parameters of the PP melt blown nonwovens investigated

The produced samples were characterized for thickness, basis weight, air permeability, fiber

diameter and die-to-collector distance were given in Table 1.

Table 1. Main production settings and their values used in experiments

The main characteristics and properties of melt-blown nonwovens can be summarised as follows:

Meltblowing is a unique system since the process generates a fine fiber not available to the other nonwoven processes. Because the micro-denier fiber (less than 0.1 denier per filament) is not really available as a nonwoven fibrous raw material, the meltblown process, which can produce such a fiber, opens new vistas of products and applications. (Dahiya et al., 2004) Microfiber nonwovens produced via meltblowing technique are suitable to be used as thermal insulators, filtration media, oil absorbents, battery separators, medical area, wipes, apparel, laminates and many other applications. (Duran&Perincek, 2010, Dutton, 2008) Meltblown nonwovens find extensive use especially in absorbent cloths and wipes; oil absorption; and filtration for liquids, gas and air. Also, very important end uses of meltblowns include sanitary applications such as hygiene and incontinence products for babies, adults and feminine hygiene. The application areas of meltblown nonwovens can be summarised as follows: (Dahiya et al., 2004)

Beside many advantages they provide, meltblowns have limited strength characteristics and poor abrasion resistance. (Farer et al., 2003) Therefore, they often are combined with other nonwovens. Spunbonds and other types of nonwovens also can be covered and refined with meltblowns. Today it is possible to implement production lines not only with spunbonds, but also with a meltblown component, to produce different types of nonwovens with an even more of a textile feeling. Approximately 40 percent of meltblowns are manufactured using a stand-alone process. The remaining meltblowns are combined with spunbonds or laminated to form other materials. Combinations with spunbonded fabrics are primarily used to make nonwoven materials with barrier properties. Another variation is the combination of meltblown with cellulose or an absorbent powder to produce a soft, strong, but still absorbent material that can retain absorbed liquid while still keeping its strength. The outcome is a combination of spunbonds (S) and meltblowns (M), resulting in SMS, or even SSMMMSS or other combinations, depending on the final product. So many different products can be manufactured and implemented from SMS to SSMMMSS. Some examples of their applications are hygiene, baby and adult diapers, medical products, protective masks for medical use, general use as a barrier layers, paper composites, work safety, protective clothing, breathing masks and combination with other nonwovens. (Rupp, 2008)


**1. Introduction**

Seagrasses, and more generally the aquatic angiosperms [1], play a key role both in marine and transitional water ecosystems (TWS). These structuring plants are considered environmental engineers to which multiple functions are associated [2]. From the morphological point of view, they reduce the impact of winds and tides on sediment resuspension, favor the sedimentation of the suspended particulate, and contrast the erosion of the seabed and the morphological structures of shallow bottoms [2]. Aquatic angiosperms characterize the bottoms of habitat 1150\* (coastal lagoons)

and 1140 (muddy or sandy bottoms emerging during low tide) *sensu* Habitat Directive 92/43/EEC, contribute to CO2 sequestration [3], and form the natural habitat for the biological communities [4] providing shelter and food for fish and macrofaunal organisms [5,6]. However, coastal areas and TWS are often very degraded and aquatic angiosperms have disappeared or are in rapid regression; that is mainly due to anthropogenic impacts such as eutrophication or pollution [7]. This was the case of the Venice Lagoon [8,9] and the lagoons of the Po Delta [10,11]. In both the TWS, aquatic angiosperms suffered from two main impacts: the overgrowth of nuisance macroalgae due to the eutrophication increase during the 1960s–1980s and the harvesting of the Manila clam *Ruditapes philippinarum* (Adams and Reeve) with hydraulic or mechanical rakes. Those activities destroyed the bottoms, uprooted the plants, and resuspended considerable quantities of sediments reducing water transparency and the growth of the plants which had survived [12].

Currently, the trophic conditions of the lagoons and ponds of the Po Delta are still bad/poor, because these environments are strongly affected by the waters of the Po River that drains the Po Valley [10,11]. Furthermore, due to the high trophic conditions, bivalves are abundant, clam fishing activities occur on a large scale, and water remains turbid. The aquatic angiosperms recorded in the past have disappeared and have been replaced by tionitrophilic macroalgae. The dominant taxa are Ulvaceae and the non-native Rhodophyceae, *Agarophyton vermiculophyllum* (Ohmi) Gurgel, J.N. Norris *et* Fredericq and *Solieria filiformis* (Kützing) P.W. Gabrielson.

In the Venice Lagoon, the effects of anthropogenic impacts have decreased since 2011 and the ecological status has started to improve [13]. Macroalgal biomass decreased significantly before the period of intense clam fishing [9] and in the last decade the dominant algal species have also changed. Ulvaceae have been largely replaced by several taxa of good-high ecological value, especially Rhodophyceae, and aquatic angiosperms are recolonizing the lagoon bottoms [7,13].

However, in all the basins of the Po Delta and in many choked areas of the Venice Lagoon plant recolonization was hampered by the lack of seeds. To favor the recolonization in the Venice Lagoon, the European Union funded the restoration project (LIFE12NAT/IT/000331—SeResto; www.lifeseresto.eu). The objective was the recolonization of the northern basin by small diffuse triggers of aquatic angiosperms which are typical of that environment: *Cymodocea nodosa* (Ucria) Ascherson, *Zostera marina* Linnaeus, *Zostera noltei* Hornemann, and *Ruppia cirrhosa* (Petagna) Grande.

In order to provide useful information for the project replication in similar TWS, this paper reports the results of the transplanting activities after the first year of plant rooting, the most common environmental parameters and nutrient concentrations in the various environmental matrices (water column, surface sediments, and suspended particulate matter (SPM)), the transplantation methods, and the most suitable environmental conditions to ensure the success of species rooting and spread.

### **2. Materials and Methods**


**Abstract**

To increase the performance of diesel engine and environment, the utilization of biofuel as a major source of renewable energy is justified. It is well understood that agri-based biofuel is always also the choice in case of utilization as biofuel because of requirement of processing and threat to food security. Therefore, scope of improvement increases as it is yet to efficiently exploit as major full in the world. There are numerous factors that influence the efficiency of a fuel and its combustion. The physiochemical properties, namely viscosity, surface tension, flash point, latent heat of vaporization, oxidation, etc., allow the fuel to work efficiently during combustion. Thus, interests in biofuels have been increased, and various experimental studies have been developed for diesel engines consisting of methanol and methyl ester of rapeseed oil. In a relevant study, to achieve ideal biofuel, various biotechnological advances at the frontiers of plant science to dissect the underlying traits for identification of fatty acid profile useful for oil production and quality are essential, thereby ensuring food security. The plantbased fuel and its efficient utilization depend upon its oil quality and quantity, which thereby can be evaluated and enhanced by various conventional and nonconventional approaches of engineering and plant sciences.

**Keywords:** biofuel, combustion, fatty acid profile, physiochemical, biotechnological


**Pavlos Alexias †,\* and Kyriakos C. Giannakoglou**

Parallel CFD & Optimization Unit, School of Mechanical Engineering, National Technical University of Athens, Irroon Polytechniou 9, Zografou 15780, Greece<EMAIL_ADDRESS>

Received: 28 November 2019; Accepted: 6 January 2020; Published: 8 January 2020

**Abstract:** In this paper, the continuous adjoint method is used for the optimization of a static mixing device. The CFD model used is suitable for the flow simulation of the two miscible fluids that enter the device. The formulation of the adjoint equations, which allow the computation of the sensitivity derivatives is briefly demonstrated. A detailed analysis of the geometry parameterization is presented and a set of different parameterization scenarios are investigated. In detail, two different parameterizations are combined into a two-stage optimization algorithm which targets maximum mixture uniformity at the exit of the mixer and minimum total pressure losses. All parameterizations are in conformity with specific manufacturability constraints of the final shape. The non-dominated front of optimal solutions is obtained by using the weighted sum of the two objective functions and executing a set of optimization runs. The effectiveness of the proposed synthetic parameterization schemes is assessed and discussed in detail. Finally, a reduced length mixer is optimized to study the impact of the length of the tube on the device's performance.

**Keywords:** mixing devices; two-phase flows; shape optimization; continuous adjoint method