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The present work used the efficiency transfer method used to calculate the full energy peak efficiency (FEPE) curves of the (2“*2” & 3“*3”) NaI (Tl) detectors based on the effective solid angle subtended between the source and the detector. The study covered the effect of the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius) on the detector efficiency. 152 An Eu aqueous radioactive source covering the energy range from 121.78 keV up to 1408.01 keV was used. In this study an empirical formula was deduced to calculate the difference between the measured and the calculated efficiencies [without self attenuation] at low and high energy regions. A proper balance between the measured and calculated efficiencies [with self attenuation] was achieved with discrepancies less than 3%, while reaching 39% for calculating values [without self attenuation] due to working with large sources, or for low photon energies.

Jatropha curcas L. (Jatropha), une espèce arbustive de la famille des Euphorbiaceae, a été reconnue comme une usine de biocarburants prometteuse pour réduire les émissions de gaz à effet de serre. Cependant, les récentes tentatives de culture commerciale en Afrique et en Asie ont échoué en raison de la faible productivité. Il est important d'élucider la diversité génétique et la relation dans les ressources génétiques mondiales de Jatropha pour la sélection de meilleurs cultivars commerciaux. Ici, la diversité génétique a été analysée en utilisant 246 accessions de la Méso-Amérique, de l'Afrique et de l'Asie, sur la base de 59 marqueurs de répétition de séquence simple et de huit marqueurs de polymorphisme d'insertion à base de rétrotransposons. Nous avons constaté que le Chiapas central du Mexique possède les ressources génétiques les plus diverses, et la dépression centrale du Chiapas pourrait être le centre d'origine. Nous avons identifié trois groupes génétiques en Méso-Amérique, dont la répartition a révélé un cline géographique distinct. L'un d'eux consiste principalement en des adhésions du centre du Chiapas. Cela suggère qu'il représente le groupe génétique d'origine. Nous avons trouvé deux accessions Veracruz dans un autre groupe, dont les ancêtres pourraient être expédiés du port de Veracruz vers l'Ancien Monde, pour être la source de tous les Jatropha africains et asiatiques. Nos résultats suggèrent la sélection humaine qui a causé une faible productivité en Afrique et en Asie, ainsi que des stratégies de sélection pour améliorer le jatropha africain et asiatique. Les cultivars améliorés dans la productivité contribueront à développer la culture commerciale de masse du Jatropha en Afrique et en Asie pour augmenter la production de biocarburants, et enfin soutiendront la lutte contre le changement climatique. Jatropha curcas L. (Jatropha), una especie de arbusto de la familia Euphorbiaceae, ha sido reconocida como una planta de biocombustible prometedora para reducir las emisiones de gases de efecto invernadero. Sin embargo, los recientes intentos de cultivo comercial en África y Asia han fracasado debido a la baja productividad. Es importante dilucidar la diversidad genética y la relación en los recursos genéticos mundiales de Jatropha para la reproducción de mejores cultivares comerciales. Aquí, se analizó la diversidad genética mediante el uso de 246 accesiones de Mesoamérica, África y Asia, basadas en 59 marcadores de repetición de secuencia simple y ocho marcadores de polimorfismo de inserción basados en retrotransposones. Encontramos que el centro de Chiapas de México posee los recursos genéticos más diversos, y la Depresión Central de Chiapas podría ser el centro de origen. Identificamos tres grupos genéticos en Mesoamérica, cuya distribución reveló un clino geográfico distinto. Uno de ellos consiste principalmente en accesiones desde el centro de Chiapas. Esto sugiere que representa el grupo genético original. Encontramos dos accesiones de Veracruz en otro grupo, cuyos antepasados podrían ser enviados desde el Puerto de Veracruz al Viejo Mundo, para ser la fuente de toda la jatrofa africana y asiática. Nuestros resultados sugieren la selección humana que causó la baja productividad en África y Asia, y también estrategias de cría para mejorar la jatrofa africana y asiática. Los cultivos mejorados en la productividad contribuirán a expandir el cultivo comercial masivo de Jatropha en África y Asia para aumentar la producción de biocombustibles, y finalmente apoyarán en la batalla contra el cambio climático. Jatropha curcas L. (Jatropha), a shrub species of the family Euphorbiaceae, has been recognized as a promising biofuel plant for reducing greenhouse gas emissions. However, recent attempts at commercial cultivation in Africa and Asia have failed because of low productivity. It is important to elucidate genetic diversity and relationship in worldwide Jatropha genetic resources for breeding of better commercial cultivars. Here, genetic diversity was analyzed by using 246 accessions from Mesoamerica, Africa and Asia, based on 59 simple sequence repeat markers and eight retrotransposon-based insertion polymorphism markers. We found that central Chiapas of Mexico possesses the most diverse genetic resources, and the Chiapas Central Depression could be the center of origin. We identified three genetic groups in Mesoamerica, whose distribution revealed a distinct geographic cline. One of them consists mainly of accessions from central Chiapas. This suggests that it represents the original genetic group. We found two Veracruz accessions in another group, whose ancestors might be shipped from Port of Veracruz to the Old World, to be the source of all African and Asian Jatropha. Our results suggest the human selection that caused low productivity in Africa and Asia, and also breeding strategies to improve African and Asian Jatropha. Cultivars improved in the productivity will contribute to expand mass commercial cultivation of Jatropha in Africa and Asia to increase biofuel production, and finally will support in the battle against the climate change. Jatropha curcas L. (Jatropha)، وهو نوع من الشجيرات من عائلة Euphorbiaceae، تم الاعتراف به كمصنع واعد للوقود الحيوي لتقليل انبعاثات غازات الدفيئة. ومع ذلك، فشلت المحاولات الأخيرة للزراعة التجارية في أفريقيا وآسيا بسبب انخفاض الإنتاجية. من المهم توضيح التنوع الوراثي والعلاقة في الموارد الوراثية للجاتروفا في جميع أنحاء العالم لتربية أصناف تجارية أفضل. هنا، تم تحليل التنوع الجيني باستخدام 246 ملحقًا من أمريكا الوسطى وأفريقيا وآسيا، استنادًا إلى 59 علامة تكرار تسلسل بسيطة وثمانية علامات تعدد أشكال الإدراج القائمة على الترانسبروسون. وجدنا أن وسط تشياباس في المكسيك يمتلك الموارد الجينية الأكثر تنوعًا، ويمكن أن يكون الكساد المركزي في تشياباس هو مركز المنشأ. حددنا ثلاث مجموعات وراثية في أمريكا الوسطى، والتي كشف توزيعها عن سلالة جغرافية متميزة. يتكون أحدها بشكل أساسي من المنضمين من وسط تشياباس. هذا يشير إلى أنه يمثل المجموعة الوراثية الأصلية. وجدنا انضمامين لفيراكروز في مجموعة أخرى، قد يتم شحن أسلافهم من ميناء فيراكروز إلى العالم القديم، ليكونوا مصدر كل الجاتروفا الأفريقية والآسيوية. تشير نتائجنا إلى الانتقاء البشري الذي تسبب في انخفاض الإنتاجية في أفريقيا وآسيا، وكذلك استراتيجيات التكاثر لتحسين الجاتروفا الأفريقية والآسيوية. ستساهم الأصناف المحسنة في الإنتاجية في توسيع الزراعة التجارية الجماعية للجاتروفا في إفريقيا وآسيا لزيادة إنتاج الوقود الحيوي، وأخيرًا ستدعم المعركة ضد تغير المناخ.

Given crude oil prices and their environmental impacts, the use of sustainable renewable alternative energies such as biofuels is rapidly progressing in numerous countries. Among biofuels, bioethanol is a renewable and clean fuel that can be obtained from the fermentation of several raw agricultural materials, including date fruit. However, the low product yield, mainly due to the low-grade nutrient content, limits its use as a promising alternative biofuel. This current study investigated bioethanol production from date by-products in Saudi Arabia and examined the impact of calcium and nitrogen sources added at different concentrations (0 to 1 g/L) on the productivity and ethanol concentration using Saccharomyces cerevisiae. Yeast extracts and ammonium chloride (NH4Cl) were tested as nitrogen sources for bioethanol fermentation from date juice. Calcium chloride (CaCl2) and calcium carbonate (CaCO3) were evaluated as calcium sources for the same purpose mentioned above. The results showed that both calcium and nitrogen sources improved ethanol production efficiencies. The addition of calcium sources such as CaCl2 at 0.4 g/L resulted in maximum ethanol concentration (41.5 ± 0.85 g/L) and the highest productivity of 0.511 g/L/h. Thus, an increase of 31.3% compared to the control sample was acquired. Ammonium chloride was found to be the best nitrogen supplement among them. Indeed, supplementing the fermentation medium with 1 g/L NH4Cl gave an optimal ethanol concentration and productivity, reaching more than 65 g/L and 0.83 g/L/h, respectively. This is an increase of 106.6%. The functional group of ethanol (C2H5OH) for all the elaborated samples was confirmed by Fourier-transform infrared spectroscopy (FTIR) and NMR analyses. Moreover, the results confirmed the high quality and purity of the bioethanol products. Thus, the “Khodhari” date variety of low market value is a privileged substrate for industrial bioethanol production. For this reason, a proposed flow diagram of a designed plant for bioethanol industrialization is provided and detailed.

The increasing global population has led to an increase in food demand; consequently, aquaculture is one of the food production sectors that has offered opportunities to alleviate hunger, malnutrition, and poverty. However, the development of a sustainable aquaculture industry has been hindered by the limited availability of natural resources as well as its negative impact on the surrounding environment. Hence, there is an urgent need to search for better aquacultural production systems that, despite their high productivity and profitability, utilize fewer resources such as water, energy, land, and capital in conjunction with a negligible impact on the environment. Biofloc technology (BFT) is one of the most exciting and promising sustainable aquaculture systems; it takes into account the intensive culture of aquatic species, zero water exchange, and improved water quality as a result of beneficial microbial biomass activity, which, at the same time, can be utilized as a nutritious aquaculture feed, thus lowering the costs of production. Furthermore, BFT permits the installation of integrated multi-trophic aquaculture (IMTA) systems in which the wastes of one organism are utilized as feed by another organism, without a detrimental effect on co-cultured species. This review, therefore, highlights the basics of BFT, factors associated with BFT for the successful production of aquatic species, the significance of this food production system for the sustainable production of economically important aquatic species, its economic aspects, drawbacks, limitations, and recommended management aspects for sustainable aquaculture.

Fermentative production of optically pure lactic acid has roused interest among researchers in recent years due to its high potential for applications in a wide range of fields. More specifically, the sharp increase in manufacturing of biodegradable polylactic acid (PLA) materials, green alternatives to petroleum-derived plastics, has significantly increased the global interest in lactic acid production. However, higher production costs have hindered the large-scale application of PLA because of the high price of lactic acid. Therefore, reduction of lactic acid production cost through utilization of inexpensive substrates and improvement of lactic acid production and productivity has become an important goal. Various methods have been employed for enhanced lactic acid production, including several bioprocess techniques facilitated by wild-type and/or engineered microbes. In this review, we will discuss lactic acid producers with relation to their fermentation characteristics and metabolism. Inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops are introduced. The operational modes and fermentation methods that have been recently reported to improve lactic acid production in terms of concentrations, yields, and productivities are summarized and compared. High cell density fermentation through immobilization and cell-recycling techniques are also addressed. Finally, advances in recovery processes and concluding remarks on the future outlook of lactic acid production are presented.

Iron limitation in vast water bodies has been linked to decreased algal productivity, despite different iron-acquiring mechanisms, and the presence of ferritin in many algal species that act as an iron internal reservoir. Therefore, iron fertilization has been proposed to increase algal biomass and photosynthesis. This, in turn, will reduce carbon dioxide in the atmosphere and increase oxygen, thereby decreasing global warming, and achieving ecological balance. In addition, algal proliferation will hopefully lead to enhancement in biodiversity, Biological pump, fish productivity and, subsequently marine food industry. Many climate geoengineering experiments in the form of ocean iron fertilization have been conducted globally in order to achieve such a purpose. However, reservations remain as the outcomes are not as promising as were previously expected. As the temporal and spatial scales of iron fertilization experiments are limited, the effects on fish productivity remain speculative. On the other hand, side effects were also recorded. The main purpose of iron fertilization, for carbon dioxide sequestration and global warming mitigation, still remains to be fully realized and verified. Several improvements and future modifications are suggested, and legal issues are discussed in this review.

Abstract Aim This study aims to use fermentation waste of ethanol production (solid and liquid) for riboflavin and recycling of bacterial biomass as biofertilizers to enhance the growth of some oily crop plants. Methods and Results Out of 10 yeast isolates from fresh milk, Clavispora lusitaniae ASU 33 (MN583181) was able to ferment different concentrations of glucose (2.5%, 5%, 7.5%, 10%, 15% and 20%) into ethanol with high efficiency at 10%. Among seven non-Lactobacillus bacterial isolates recovered from cheese samples, two bacterial isolates Bacillus subtlis-SR2 (MT002768) and Novosphingobium panipatense-SR3 (MT002778) were selected for their high riboflavin production. Different media (control medium, fermentation waste medium and a mixture of the fermentation waste medium and control medium [1:1]) were used for riboflavin production. These media were inoculated by a single or mixture of B. subtlis-SR2, N. panipatense-SR3. The addition of the waste medium of ethanol production to the control medium (1:1) had a stimulatory effect on riboflavin production whether inoculated with either a single strain or a mixture of B. subtlis-SR2 and N. panipatense-SR3. A mixture of fermentation waste and control media inoculated with N. panipatense produced a high riboflavin yield in comparison with other media. Inoculation of Zea mays and Ocimum basilicum plants with either the bacterial biomass waste of riboflavin production (B. subtlis or N. panipatense) or a mixture of B. subtlis and N. panipatense) shows a stimulatory effect on the plant growth in comparison with control (uninoculated plants). Conclusions These results demonstrate the possibility of minimizing the cost of riboflavin and biofertilizer manufacturing via interlinking ethanol and riboflavin with the biofertilizer production technology. Significance and Impact of Study This study outlines the methods of evaluating the strength of spent media by applying procedures developed in the vitamin production industries. Furthermore, bacterial biomass waste can act as an environmentally friendly alternative for agrochemicals.