Design And Analysis Of A Double Carrier Modulation/Differential Detection Technique For Optical Fiber Communications

Fiber optic long haul transmissions have been globally deployed at a staggering rate. All of the installed networks are using Intensity Modulation/Direct Detection (IM/DD). Although the IM/DD systems are proven and used widely, these networks are still subjected to many problems. The main problems associated with long haul transmission are; high dispersion and losses incurred by the fiber, and the inability of the receiver circuit to regenerate the transmitted bits. This is because of low signal power and inter-symbol interference, in addition to the masking noises. The recovery technique in the conventional receivers based on the IM/DD scheme uses an injected voltage level as a threshold into a decision circuit, which decides whether the incoming bit is a 0 or a 1. This scheme has two inherent problems; the instability of the injected threshold voltage, and the complexity of a dynamic threshold processing. As the threshold voltage has its own noise and fluctuation, it adds to the deterioration of the signal, thus limits the systems performance. Meanwhile, due to the random nature of the incoming bits, coupled with the masking noises and jitters, the threshold voltage level cannot be set at a fixed value, and therefore a dynamic voltage threshold adjustment is required. The demand of high data rate and long transmission distance impose much difficulty, therefore new approaches and techniques have to be applied to improve the system and solve these problems. This led to the development of new techniques for the system performance improvement

An Experimental And Numerical Investigation Of Machining Chips Behavior In Compaction And Consolidation Processes

Manufacturing processes such as machining and cutting often produce metal wastes (e.g. machining chips) that can be costly to recycle using conventional methods that involve melting. The Friction Extrusion Process (FEP) and Friction Consolidation Process (FCP) provide a novel method of recycling machining chips to produce useful products such as wires or consolidated disks without melting. These solid-state processes do not require complicated equipment and offer a cost effective and environment friendly alternative route to metal waste recycling. The current study was aimed at achieving an understanding of the mechanical and thermal behavior of machining chips during compaction and consolidation processes that occur in FEP and FCP, which is currently lacking. An integrated experimental and numerical approach was employed. Experiments were carried out to provide opportunities to measure and extract stress, strain and thermal response information on machining chip specimens during and/or after compaction and consolidation tests. The experimental data was analyzed and findings were used as a basis to develop mathematical models for the mechanical and thermal behavior of the chips material during and after compaction and consolidation. These models took into account the change in density of the chips material during compaction and consolidation process. The model parameter values as functions of the relative density were extracted from experimental measurements of mechanical and thermal responses. These models were implemented in user subroutines (UMAT) and user defined functions (UDFs) for a commercial finite element and numerical simulation software packages. The numerical simulations of validation experiments were carried out to predict the mechanical and thermal behavior of chips material in the validation experiments. Model predictions were validated through comparisons with experimental measurements and were found to agree well with experimental measurements

Resource Management Techniques in Cloud-Fog for IoT and Mobile Crowdsensing Environments

The unpredictable and huge data generation nowadays by smart devices from IoT and mobile Crowd Sensing applications like (Sensors, smartphones, Wi-Fi routers) need processing power and storage. Cloud provides these capabilities to serve organizations and customers, but when using cloud appear some limitations, the most important of these limitations are Resource Allocation and Task Scheduling. The resource allocation process is a mechanism that ensures allocation virtual machine when there are multiple applications that require various resources such as CPU and I/O memory. Whereas scheduling is the process of determining the sequence in which these tasks come and depart the resources in order to maximize efficiency. In this paper we tried to highlight the most relevant difficulties that cloud computing is now facing. We presented a comprehensive review of resource allocation and scheduling techniques to overcome these limitations. Finally, the previous techniques and strategies for allocation and scheduling have been compared in a table with their drawbacks

Analysis and Forecast of Mining Fatalities in Cherat Coal Field, Pakistan

Mineral exploitation contributes to the economic growth of developing countries. Managing mineral production brought a more disturbing environment linked to workers' causalities due to scarcities in the safety management system. One of the barriers to attaining an adequate safety management system is the unavailability of future information relating to accidents causing fatalities. Policymakers always try to manage the safety system after each accident. Therefore, a precise forecast of the number of workers fatalities can provide significant observation to strengthen the safety management system. This study involves forecasting the number of mining workers fatalities in Cherat coal mines by using Auto-Regressive Integrating Moving Average Method (ARIMA) model. Workers' fatalities information was collected over the period of 1994 to 2018 from Mine Workers Federation, Inspectorate of Mines and Minerals and company records to evaluate the long-term forecast. Various diagnostic tests were used to obtain an optimistic model. The results show that ARIMA (0, 1, 2) was the most appropriate model for workers fatalities. Based on this model, casualties from 2019 to 2025 have been forecasted. The results suggest that policymakers should take systematic consideration by evaluating possible risks associated with an increased number of fatalities and develop a safe and effective working platform

The robust catalysts (Ni1−–Mo /doped ceria and Zn1−–Mo /doped ceria, x = 0.1 and 0.3) for efficient natural gas reforming in solid oxide fuel cells

Nickel is a promising catalyst in Solid Oxide fuel cell (SOFC) due to its electrocatalytic performance, however, the practical utilization of Ni-based materials is hindered by the undesirable carbon deposition during methane decomposition. Herein, molybdenum is incorporated into the Ni- and Zn-based cermets (Ni1−x–Mox/GDC and Zn1−x–Mox/GDC, x = 0.1 and 0.3) to enhance electrocatalytic properties and avoid the carbon deposition during cell operation. The desired composites are synthesized by the impregnation method and adopted as anode in SOFCs. The catalytic activity for methane oxidation has been significantly improved due to the introduction on Mo, which hindered the carbon deposition due to higher graphitization and abundant active sites accessible to fuel. The detailed Raman spectroscopy and conductivity analysis revealed that addition of Mo reduced the amount of deposited carbon and enhanced the electrical conductivity. By using natural gas, as a fuel, the as-prepared Mo-doped Ni–GDC rendered a maximum power density of 690 mW cm−2 at 600 °C. It is worth mentioning that the achieved stable power density is one of the best in existing literature. The current study presents a novel strategy to improve the catalytic behavior of electrode materials and demonstrate the optimal performance at low operating temperature

Improving the Antibacterial Activity of Ceftazidime by Inulinase Purified from Staphylococcus Aureus

Inulinase is an enzyme catalyzing the hydrolysis of inulin, a plant stored polysaccharide, into fructoses and fructo- oligosaccharides that have a large spectrum of applications ranging from food industry to bioethanol production and pharmacology.Eight isolates of Staphylococcus aureus were isolated from agricultural rhizosphere soil samples with isolation percentage(32%)   and screened for higher inulinase production and found that Staphylococcus aureusS3 was the best producer. Inulinase was  partially purified with ammonium sulfate at 70% saturation and the specific activity reached to (7.01)U/mg protein. Inulinase led to enhancement ceftazidime activity against the bacteria and  gram positive bacteria more sensitive than negative bacteria to combination of inulinase and ceftazidime. These finding indicate that antistaphylococcal activity of ceftazidime antibiotic has increased in the presence of inulinase enzyme and the inulinase may be useful adjuvant agent for the treatment of S. aureus infections in combination with this antibiotic

Sectorial study of technological progress and CO 2 emission: Insights from a developing economy

ABSTRACT(#br)Many studies have stated that technological progress is an important driver of carbon dioxide (CO 2 ) emissions and energy consumption. However, the sectorial differences in the relationship between CO 2 emission and technological progress have been understudied by scholars. This study attempts to fill such gap by empirically investigating the impact of technological progress on CO 2 emissions. A quantile regression method and balanced national data from Pakistan covering the period of 1991–2017 are used to establish relationships among the variables. The results and analysis reveal that the agriculture and services sectors have a negative impact on CO 2 emissions, whereas the construction, manufacturing, and transportation sectors greatly contribute to these emissions. The lower, medium, and upper-level emitters are used to understand the percentile conditions of each variable. A scenario analysis is also performed to forecast the reduction proportion of CO 2 emissions for the best understanding and policy implication in 2030, 2035, and 2040. The results of this study provide useful insights into the relationship between technological progress and CO 2 emissions and suggest different scenarios for reducing CO 2 emissions in the future that can support policy makers and planners

Identification of a Novel Therapeutic Target against XDR Salmonella Typhi H58 Using Genomics Driven Approach Followed Up by Natural Products Virtual Screening

Typhoid fever is caused by a pathogenic, rod-shaped, flagellated, and Gram-negative bacterium known as Salmonella Typhi. It features a polysaccharide capsule that acts as a virulence factor and deceives the host immune system by protecting phagocytosis. Typhoid fever remains a major health concern in low and middle-income countries, with an estimated death rate of ~200,000 per annum. However, the situation is exacerbated by the emergence of the extensively drug-resistant (XDR) strain designated as H58 of S. Typhi. The emergence of the XDR strain is alarming, and it poses serious threats to public health due to the failure of the current therapeutic regimen. A relatively newer computational method called subtractive genomics analyses has been widely applied to discover novel and new drug targets against pathogens, particularly drug-resistant ones. The method involves the gradual reduction of the complete proteome of the pathogen, leading to few potential and novel drug targets. Thus, in the current study, a subtractive genomics approach was applied against the Salmonella XDR strain to identify potential drug targets. The current study predicted four prioritized proteins (i.e., Colanic acid biosynthesis acetyltransferase wcaB, Shikimate dehydrogenase aroE, multidrug efflux RND transporter permease subunit MdtC, and pantothenate synthetase panC) as potential drug targets. Though few of the prioritized proteins are treated in the literature as the established drug targets against other pathogenic bacteria, these drug targets are identified here for the first time against S. Typhi (i.e., S. Typhi XDR). The current study aimed at drawing attention to new drug targets against S. Typhi that remain largely unexplored. One of the prioritized drug targets, i.e., Colanic acid biosynthesis acetyltransferase, was predicted as a unique, new drug target against S. Typhi XDR. Therefore, the Colanic acid was further explored using structure-based techniques. Additionally, ~1000 natural compounds were docked with Colanic acid biosynthesis acetyltransferase, resulting in the prediction of seven compounds as potential lead candidates against the S. Typhi XDR strain. The ADMET properties and binding energies via the docking program of these seven compounds characterized them as novel drug candidates. They may potentially be used for the development of future drugs in the treatment of Typhoid fever

Clinical course and disease outcomes in hospitalized patients with 2019 novel corona virus disease at Ibn- Al Khateeb Hospital in Baghdad, Iraq

Background: the novel coronavirus (2019-ncov), formally known as severe acute respiratory syndrome coronavirus 2 (sars-cov-2), the etiological cause of the (corona virus disease 2019) covid-19, appeared in wuhan, hubei province, china. On 11 march 2020, the world health organization (who) declared this disease as a pandemic. As new information on the clinical characteristics, treatment options, and outcomes for covid-19 emerges approximately every hour, physicians should keep themselves up-to-date on this topic. Objective: to study the demographic features, clinical signs and symptoms and certain vital and laboratory findings of covid-19 hospitalized cases; and to identify the used medication, complications, length of stay at the hospital and disease outcomes of confirmed covid-19 cases. Patients and methods: a descriptive cross-sectional study with analytic elements was conducted at ibn-al khateeb hospital, baghdad on covid-19 patients admitted to the hospital from 1st of march to 4th of may 2020. All inpatients of all age groups, diagnosed as covid-19 and had a definite outcome (recovered and discharge or death) during the period of the study were included. Results: the mean age ± sd for the patients included in the study was = 37.9±18.85 years, with 51.2% being males. The outcome was statistically significantly associated with age, marital status, hypertension, disease severity at admission and length of stay at hospital. Conclusion: this study found that age was associated with disease outcome. Care, attention and monitoring should be taken into consideration for hypertensive patients. Patients’ initial signs and symptoms of dyspnea, weakness and sore throat were significantly associated with disease outcome

Chromium removal from aqueous solution using bimetallic Bi\u3csup\u3e0\u3c/sup\u3e/Cu\u3csup\u3e0\u3c/sup\u3e-based nanocomposite biochar

Chromium (Cr), due to its greater contamination in aquifers and distinct eco-toxic impacts, is of greater environmental concern. This study aimed to synthesize nanocomposites of almond shells biochar (BC) with zerovalent bismuth and/or copper (Bi0/BC, Cu0/BC, and Bi0–Cu0/BC) for the removal of Cr from aqueous solution. The synthesized nanocomposites were investigated using various characterization techniques such as XRD, FTIR spectroscopy, SEM, and EDX. The Cr removal potential by the nanocomposites was explored under different Cr concentrations (25–100 mg/L), adsorbent doses (0.5–2.0 g/L), solution pH (2–8), and contact time (10–160 min). The above-mentioned advanced techniques verified successful formation of Bi0/Cu0 and their composite with BC. The synthesized nanocomposites were highly effective in the removal of Cr. The Bi0–Cu0/BC nano-biocomposites showed higher Cr removal efficiency (92%) compared to Cu0/BC (85%), Bi0/BC (76%), and BC (67%). The prepared nanocomposites led to effective Cr removal at lower Cr concentrations (25 mg/L) and acidic pH (4.0). The Cr solubility changes with pH, resulting in different degrees of Cr removal by Bi0–Cu0/BC, with Cr(VI) being more soluble and easier to adsorb at low pH levels and Cr(III) being less soluble and more difficult to adsorb at high pH levels. The experimental Cr adsorption well fitted with the Freundlich adsorption isotherm model (R 2 \u3e 0.99) and pseudo-second-order kinetic model. Among the prepared nanocomposites, the Bi0–Cu0/BC showed greater stability and reusability. It was established that the as-synthesized Bi0–Cu0/BC nano-biocomposite showed excellent adsorption potential for practical Cr removal from contaminated water