Advanced ultrafiltration technology for lignocelluloses recovery and purification from thermomechanical pulp (TMP) mills process waters

Process waters of thermomechanical pulp (TMP) mills contain a large valuable quantity of lignocellulosic materials that end up in the wastewater for biological treatment. In recent years, interest in utilizing such compounds has increased, and plenty of applications have been proposed. Thus, the recovery of hemicelluloses and lignin from these process waters as value-added chemicals would be beneficial for TMP mills not only to increase their profitability and competitiveness but also to reduce the organic loading to the wastewater treatment facility. However, this implies adoption of different types of appropriate separation technologies. Among the proposed separation methods, membrane technologies have been studied in a wider range of perspectives, and have been shown to play a key role in products recovery and purification in biorefining processes. In this study, the feasibility of the advanced UF technology for hemicellulose recovery and concentration from thermomechanical pulp (TMP) mill process waters was evaluated. In particular, the influence of ultrafiltration membrane cut-offs and volume reduction factors on membrane flux, and recovery and purity of hemicelluloses were investigated. Based on this study, the three tested membranes had shown different ability to recover hemicelluloses from the TMP process water. 5KDa membranes achieved the highest percent recovery of hemicellulose (95.7%), followed by 10KDa membranes 89.2% for the volume reduction (VR) of 95%. 30KDa membranes had the lowest percent recovery of 52% for VR value of 95%. Compared to 5kDa membranes, a cut-off of 10kDa seems to be feasible for the separation of lignin from hemicelluloses; it retained hemicelluloses while allowing the lignin to pass through it. Retentions of lignin were markedly low with the tested 10kDa membranes, compared with hemicelluloses retention. Volume reduction had a significant influence on the amount of hemicelluloses and lignin held back by the membrane. In this study also the characteristics of permeates and concentrates of UF membrane with different cut-offs were studied

Electronic Contract and its Effects According to the Sudanese Electronic Transactions law for the Year (2007) A Comparative Study

       The most important thing that distinguishes the electronic contract from the traditional contract is the means through which it passes through it through an electronic environment that uses modern means of communication, especially the internet. The study aimed at: To learn about the concept of e-contract and its advantages. Highlighting the languages ​​of affirmation and electronic acceptance and its characteristics. The study followed the descriptive historical descriptive method. The study found many results, including: Electronic contracts are usually concluded online, a network open to users around the world, especially in the case of mutual exchange and acceptance through the site, it creates a problem on how to determine the personality of the parties to the contractual process for the purpose of providing In this case, the owner of the site that is exchanging the offer and acceptance of the other must identify the persons who use it, if not the obligor or the owner of the site itself, Sudan is one of the first Arab countries that has an electronic transactions law is the law of (2007). Only Jordan, the Emirate of Dubai, Bahrain, Tunisia and Lebanon. preceded this. In addition, the method of expression in contracts for acceptance of online contracts is consistent with the method of contracting. An icon or by entering private information, and we find no value for silence as an expression of acceptance in electronic contracts. The study recommended the following: We propose to amend some articles of the Sudanese civil law to be in a way that shows (concluding contracts by means of modern communication) to accommodate all the new developments in communications, and the means of contracting modern, such as the Internet. As well as the creation of special websites on the net providing advice and guidance to provide protection to the less experienced party in the electronic contract.        أهم ما يميز العقد الالكتروني عن العقد التقليدي هو تلك الوسيلة التي يمر عن طريقها، بحيث يتم من خلال بيئة الكترونية تستخدم فيها وسائل الاتصال الحديثة وعلى رأسها شبكة الانترنت. هدفت الدراسة إلى التعرف على مفهوم العقد الإلكتروني ومميزاته. وإبراز لغات الإيجاب والقبول الإلكتروني وخصائصه. اتبعت الدراسة المنهج الوصفي التاريخي الاستقرائي. توصلت الدراسة إلى العديد من النتائج من بينها: إن العقود الإلكترونية مبرمة عادة عبر الإنترنت، وهي شبكة مفتوحة أمام المستخدمين في جميع أنحاء العالم خاصة في حالة تبادل الإيجاب والقبول من خلال الموقع، فإن ذلك يخلق مشكلة تتعلق بكيفية تحديد شخصية طرفي العملية التعاقدية وذلك لغرض توفير الأمان القانوني لها، ففي هذه الحالة يجب على صاحب الموقع الذي يجري تبادل الإيجاب والقبول غيره، أن يقوم بتحديد الأشخاص الذين يستخدمونه، هذا إن لم يكن الموجب أو القابل صاحب الموقع نفسه، السودان من أوائل الدول العربية التي لديها قانون للمعاملات الإلكترونية وهو قانون المعاملات الإلكترونية لسنة (2007م) ولم يسبقه في ذلك إلا الأردن، إمارة دبي، البحرين، تونس، لبنان، بالإضافة إلى أن أسلوب التعبير في العقود عن القبول في العقود التي تتم عبر الإنترنت يكون متماشياً مع طريقة التعاقد فقد يكون عن طريق النقر عدة مرات على إيقونة ما أو عن طريق إدخال معلومات خاصة، ولا نجد قيمة للسكوت باعتباره تعبيراً عن القبول في العقود الإلكترونية. أوصت الدراسة بالآتي: نقترح تعديل بعض مواد القانون المدني السوداني لتكون بشكل يوضح (إبرام العقود بوسائل الاتصال الحديثة) لتستوعب كل ما يستجد على صعيد الإيصالات، ووسائل التعاقد الحديثة كالإنترنت. كذلك استحداث مواقع إلكترونية خاصة على الشبكة تقدم النصائح والإرشادات لتوفير الحماية للطرف الأقل خبرة في العقد الإلكتروني

Integer Representations of the Generalized Symmetric Groups

In this paper, we construct a mixed-base number system over the generalized symmetric group $G(m,1,n)$, which is a complex reflection group with a root system of type $B_n^{(m)}$. We also establish one-to-one correspondence between all positive integers in the set $\{1,\cdots,m^nn!\}$ and the elements of $G(m,1,n)$ by constructing the subexceedant function in relation to this group. In addition, we provide a new enumeration system for $G(m,1,n)$ by defining the inversion statistic on $G(m,1,n)$. Finally, we prove that the \textit{flag-major index} is equi-distributed with this inversion statistic on $G(m,1,n)$. Therefore, the flag-major index is Mahonian on $G(m,1,n)$ with respect to the length function $L$

An Inversion Statistic on the Hyperoctahedral Group

In this paper, we introduce an inversion statistic on the hyperoctahedral group $B_n$ by using an decomposition of a positive root system of this reflection group. Then we prove some combinatorial properties for the inversion statistic. We establish an enumeration system on the group $B_n$ and give an efficient method to uniquely derive any group element known its enumeration order with the help of the inversion table. In addition, we prove that the \textit{flag-major index} is equi-distributed with this inversion statistic on $B_n$

Advanced separation and anaerobic digestion technologies for value-added bioproducts and biofuel from pulp and paper mill wastes

In the first research project, the extraction of hemicellulose from the process water and synthetic hydrolyzate using liquid-liquid extraction (LLE) was examined. Specifically, the effects of the main experimental variables (the type of solvent, hydrolyzate to solvent volume ratio, and pH) on extraction performance were explored. The tested solvents showed varying affinity and selectivity to recover hemicellulose. It was found that the hemicellulose extraction efficiency of n-hexane (71.03%) and tributyl phosphate (TBP) (72.34%) was higher than that of 1-butanol (62.36%), and toluene (67.03%) at a solvent: hydrolyzate volume ratio of 1:3. A pH value of 4.3, a phase ratio of 1:3 mL/mL, and an extraction time of 30 min were considered optimal conditions for hemicellulose extraction. In the second study, the thermophilic submerged anaerobic membrane bioreactor (ThSAnMBR) technology was used for pulp and paper primary sludge treatment, and both biological and membrane performance were evaluated. The biological performance was studied in terms of biogas production, solids reduction, chemical and structural changes of the digestate, and permeate quality under various operating conditions. While the effect of primary sludge on the membrane performance and fouling was systematically investigated. Several experimental parameters were investigated including solids retention time (SRT) (32- 55 days), hydraulic retention time (HRT) (3-8 days), organic loading rates (OLRs) (2.5-6.8 kg-COD/m3d), temperature (50±1°C), membrane fouling and cleaning frequency. Membrane performance was evaluated by monitoring its flux and corresponding transmembrane pressure as well as changes in its chemical and physical properties resulting from operating conditions using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), contact angle, and pore size measurement. [...

Design of Wireless Automatic Microwave Antenna Alignment System

Microwave link aligning is an important operation in communication systems. Misalignment in line of sight link due to rain, wind etc considered the basic problem that faced the microwave system. This problem caused a direct terminating of the microwave link. Automatic antenna alignment will guarantee best communication at the link’s ends without any risks of human interface. This paper presented a low cost design of an automatic antenna alignment system based on arduino and using Xbee wireless technology. The design in the paper is automatically adjusting the horizontal and vertical angles in the transmitter and receiver sides of the microwave link. The controller compared the measured values of these two angles with a reference values. The correction of the error in the angles is done by moving the antenna towards the correct position. The design was tested in different angles positions and the results were reported in the paper. The simulation results ensure that the system works successfully

Social Media as a Political Platform in Africa: A Bibliometric Analysis

This study employs bibliometric analysis to scrutinize the pivotal journals, institutions, and countries at the nexus of social media and political discourse in Africa. Utilizing VOSviewer, a dataset of 123 publications from 2013 to 2023 was culled from Scopus Database. The analysis encompasses diverse methodologies, each tailored to the specific nature of bibliometric investigation. "Information, Communication and Society" emerged as the foremost journal in this domain, while South Africa spearheaded contributions, followed by the United States and the United Kingdom. The National Research Foundation played a prominent role as an influential institution. Notably, four distinct thematic clusters emerged, illuminating significant research areas such as the role of political platforms on human rights, the influence of social media on community engagement, the impact of media platforms on African conflicts, and social media's contribution to freedom through discourse. This study represents a pioneering bibliometric endeavor in comprehensively gauging the landscape of social media and politics in Africa, offering valuable insights for scholars and policymakers navigating this dynamic terrain.

Design of Wireless Control Mixing System of Liquids using Raspberry Pi Device

The use of automation technology in the field of mixing liquids assists to reduceerrors in this process which improved the quality of products. Liquid mixing machines often require a number of workers in order to operate the machines which increases the risk to them. This paper proposes wireless design for mixing three different liquids using raspberry pi technology. The design aims to provide lower risk rates, lower cost and high accuracy. The mechanism of mixing the three liquids and filling the tanks is done automatically using raspberry pi and ultrasonic sensors. Users must have to login with the correct IP address and password in order to access the application using a Wi-Fi connection. The system consists of three sub tanks filling the main tank in specifec ratio for each one. The programming of this implemention is accompleshed using python language. The experimental results have proven that the system works successfully and it can be applied in a real environment