Treatment of contaminated Flowback water in shale gas development

Flowback water from shale gas well drilling has a high TDS (total dissolved solids) content, ranging from 5000 ppm to 261,000 ppm, along with a TSS (total suspended solids) content of 300–3000 mg/L. Recently, the rapid expansion of shale gas production in Marcellus Formation has raised serious environmental concerns about the large amount of flowback water in this area. In this project a process based on ceramic membrane filtration and ion-exchange is optimised for the treatment of the flowback water from Marcellus Formation. Mixed bed ion-exchange will then be employed to reduce the high TDS concentration of flowback water. Finally, a preliminary cost estimation of the proposed treatment process will be conducted. The studied process contains a combination of two MF (microfiltration) membranes. After treatment, all TSS and >99% of TDS should be successfully removed from the flowback water to meet the criteria for surface discharge. The cost estimation of the treatment is expected to be around 18.4 $/m

Characterization of the inessential endomorphisms in the category of Abelian groups

An endomorphism f of an Abelian group A is said to be inessential (in the category of Abelian groups) if it can be extended to an endomorphism of any Abelian group which contains A as a subgroup. In this paper we show that f is as above if and only if (f − v idA)(A) is contained in the maximal divisible subgroup of A for some v ∈ Z

The impact of Djezzy service quality in reaching the Customer’s loyalty Case study of a sample from Djezzy customers –Laghouat-

هدفت هذه الدراسة إلى الكشف عن الأثر الذي تلعبه جودة الخدمة المقدمة من طرف جازي في تحقيق ولاء زبائنها. و قصد تحقيق أهداف هذه الدراسة تم الاعتماد على طريقة الاستقصاء عن طريق الاستبيان، و ذلك بتصميم استبيان و توزيعه على عينة من زبائن جازي بمدينة الأغواط، و قمنا باستخدام برنامج SPSS في تحليل بيانات الاستبيان مستخدمين في ذلك أساليب إحصائية مختلفة لعرض النتائج واختبار الفرضيات. و من أهم النتائج المتوصل إليها نذكر أبرزها كما يلي: يوجد تأثير ذو دلالة إحصائية لجودة الخدمة المقدمة من طرف جازي في ولاء الزبائن؛ هناك فروق ذات دلالة إحصائية لولاء زبائن جازي تعود إلى متغير المستوى التعليمي؛ لا توجد فروق ذات دلالة إحصائية لولاء زبائن جازي تعود إلى متغيرات الجنس، العمر، الحالة العائلية و نمط الاشتراك.The present study aims to unveil the impact of the service quality provided by Djezzy in gaining its customer’s loyalty. In order to reach the objectives of the study we adopted a method of survey through a questionnaire which was structured and distributed to a sample of Djezzy customers in the wilaya of Laghouat. We used SPSS program in the questionnaire data analysis using different statistical methods to show the results and test the hypotheses. Among the most important results obtained: There is a statistically significant effect of the service quality provided by Djezzy on its customers’ loyalty; There are significant differences of Djezzy customers’ loyalty due to the variable of educational level; There are no significant differences of Djezzy customers’ loyalty due to the variables of gender, age, family status, and payment mode

The Impact of Information and Communications Technology on Innovative Teaching - Teachers’ Perspective

Since the turn of the millennium, individuals have become ceaselessly dependent on new technologies. In both teachers’ and learners’ lives, the use of Information and Communications technology has become decisive; teachers endeavour to enhance their way of teaching through the adoption of novel ways of teaching and the introduction of a large amount of fun, such aspects are present in the virtual world of technology. In fact, this study aims to investigate the impact of ICTs on innovative teaching. This is to say that making use of ICTs in the academic setting would certainly accentuate teachers’ performance, and thus a positive students’ response. The research was designed at Teachers’ Higher College-ENS Laghouat, among thirty teachers of Arabic, French and English language, involving a questionnaire of twenty-five questions. The study revealed a significant impact of Information and Communications technology on innovative teaching

Cloning, Expression, Primary Structure, and Insertion Mutagenesis of the Pyruvate Formate-Lyase Enzyme of Aeromonas Hydrophila.

The pyruvate formate-lyase enzyme (Pfl), a key enzyme in alcoholic fermentation, catalyzes the anaerobic conversion of pyruvate into acetyl-CoA and formate in prokaryotes. The pyruvate formate-lyase gene (pfl) of the facultative anaerobe Aeromonas hydrophila was cloned and sequenced. Subsequently, the Pfl was characterized based on the deduced amino acid sequence and evaluated in vivo following insertion mutagenesis. Finally, the pathogenesis of a defined mutant was compared to wild type A. hydrophila in channel catfish. The pfl of A. hydrophila was identified from two recombinant pBluescript SK(-) clones excised from a $\lambda$ ZAP II phage library. Both clones carried the same 9.15 Kbp insert, oriented in opposite directions, and expressed two polypeptide of 85 & 82 KDa sizes regardless of isopropyl-B-D-thiogalactoside induction. Dideoxy sequencing of a 4.8 Kbp subclone expressing the two immunoreactive polypeptides identified a 2280 base open reading frame (ORF), with 70% sequence homology to the E. coli pfl. The ORF encodes an 85.5 KDa protein containing 760 amino acid residues with 85.5% homology to the E. coli Pfl peptide sequence. The Aeromonas Pfl secondary structure consists of 46% $\alpha$-helices and 39% $\beta$-sheets. Catalytically important adjacent cysteine residues in E. coli Pfl at positions 419-420 were also located at the same positions in the A. hydrophila Pfl. A free radical identified at glycine-735 residue in the cloned enzyme was also in the same position as in E. coli Pfl. A candidate trypsin cleavage site, located between arginine residues at 624-625 positions in A. hydrophila Pfl, was confirmed by the presence of a 68 KDa trypsin resistant fragment. Insertion mutagenesis of the pfl with a kanamycin resistant marker (kan) resulted in isolating an obligate aerobic A. hydrophila pfl mutant strain, which was characterized phenotypically by anaerobic growth on pyruvate and antibiotic resistance profile. Polymerase chain reaction experiments confirmed the insertion of the kan marker into the mutant chromosome and the occurrence of a double-crossover homologous recombination event. No significant difference was noticed in the LD\sb{50} in channel catfish injected with either the parent or the mutant strain, indicating that the Pfl may not play an important role in the pathogenesis of acute A. hydrophila infections