Improve Bounds of some Arithmetical Functions

نبين في هذا البحث استخدام دالة المعيار للحصول على بعض المعلومات عن القيد السفلي لدالة ريمان زيتا    بحيث  هذا الموضوع درس عميقا من قبل العالم هلبيردنك (انظر المصدر الاول). الحصول على قيد لداله ريمان زيتا في شريط الفترة الحقيقية        يكون من الصعب جدا وذلك للعديد من الاسباب التي تعود الى تصرفات تلك الداله في ذلك الشريط. الهدف من هذا البحث هو اثبات    له قيد سفلي دقيق عندما الجزء الحقيقي من   يكون جدا قريب من الخط 1.We show in this article the use of the norm function to get a new lower bound of Riemann-Zeta function  where.  This subject has been studied deeply by Hilberdink [HIL, 12]).  Getting a bound for the Riemann-Zeta function  in the critical strip is more challenging  for many reasons related to the behavior of the  Riemann-Zeta function in that strip. In the other words, the aim of this article  is to prove that  has a strict lower bound when the real part  is very closed to the line 1.  We state this in the  main theorem of this paper

A Modified Vector Space Model For Protein Retrieval.

This paper provides an enhancement of an existing method of information retrieval which is a modification of Vector Space Model for information retrieval. This enhanced model is modified to be applied on protein sequence data whereas the normal vector space model has been applied on text data. The results show that the enhanced model achieved very good results in performance but the setup time is somehow high for a large collection of protein sequence

A short review on graphene derivatives towards photoelectrochemical water splitting

Graphene oxide is vital in photoelectrochemical (PEC) water splitting, serving as an essential photoanode material. Its semiconducting nature allows for the generation of photocurrents, promoting water oxidation at the anode and contributing to hydrogen production efficiency. Additionally, graphene is a two-dimensional carbon allotrope that has quickly emerged as a highly promising material in PEC water splitting, potentially transforming renewable energy and sustainable hydrogen generation. Graphene improves PEC water-splitting efficiency by facilitating efficient charge transport, rapid electron transfer, and effective redox reactions at the electrode-electrolyte interface. It possesses high electrical conductivity, a large specific surface area, and excellent charge carrier mobility. Its unique band structure enables efficient light absorption across a broad spectrum, including visible light, resulting in better light-to-electricity conversion. Furthermore, the inherent catalytic activity of graphene speeds up the oxygen evolution process (OER), increasing water oxidation and aiding hydrogen gas production

Effects of service marketing mix on Umrah customer satisfaction: empirical study on Umrah traveling industry in Malaysia

The objective of this research was to The purpose of this research was to study the customer perception toward marketing mix (product, price, place, promotion, people, process, physical evidence, marketing communication and after sale service), and customer satisfaction of Umrah traveling industry in Malaysia”. “A quantitative study was adopted for collecting data. The customers who performed Umrah more than once were on the focus of this study. The necessary data were collected from 384 respondents through a structured questionnaire using a convenience sampling technique”. “Customer perception toward all dimensions service marketing mix have a positive impact on customer satisfaction. The present study enables the understanding of consumer behavioural features, especially in term of customer satisfaction in Umrah services, particularly in Malaysia and the overall Umrah industry”. “The service sector plays a pivotal role in a country’s economy specifically in Malaysia and part of this sector services is the Umrah services, becomes it is important for commercial activities and contributes to the quality of life. In short, it implies that the role of Umrah services is regarded as a basic need of life”. “Thus, it is imperative to fulfil the requirements and expectations of customers in multifarious backgrounds. This study is an initial effort in investigating the satisfaction of Umrah customers in Malaysia, including their contributing factor, name service marketing mix

Effect of ceramic coating in combustion and cogeneration performance of Al2O3 porous medium

In this work, the effect of SiC-, Ni-, and Cr-based coating on the performance of porous medium burner are evaluated. A dip-coating technique was used to coat SiC, Ni, and Cr powders on a pre-sintered porous Al2O3 substrate. The morphological properties of the sintered Al2O3 plain substrates and coating layer were observed using a light microscope and scanning electron microscopy. The combustion analyzer has been calibrated and used to measure the emissions during the experiment. Thermoelectric cells were used in the cogeneration system to generate electricity from the porous medium burner. The results show a significant improvement in the maximum surface flame temperature and combustion emissions over the plain substrate. The highest recorded surface flame temperature at flow rate of 0.25 L/min was 750°C for SiC-coated, 741°C for Cr-coated, 739°C for Ni-coated and plain substrate registered a temperature of only 634 °C. An 18% increase in flame temperature was recorded for SiC-coated substrate when compared to the plain substrate. Moreover, the coated substrate reduced the emissions CO, COu and NOx. It was also found that; SiC-coated substrate reported the best overall power output when compared to the plain substrate

Detection of outliers in high-dimensional data using nu-support vector regression

Support Vector Regression (SVR) is gaining in popularity in the detection of outliers and classification problems in high-dimensional data (HDD) as this technique does not require the data to be of full rank. In real application, most of the data are of high dimensional. Classification of high-dimensional data is needed in applied sciences, in particular, as it is important to discriminate cancerous cells from non-cancerous cells. It is also imperative that outliers are identified before constructing a model on the relationship between the dependent and independent variables to avoid misleading interpretations about the fitting of a model. The standard SVR and the μ-ε-SVR are able to detect outliers; however, they are computationally expensive. The fixed parameters support vector regression (FP-ε-SVR) was put forward to remedy this issue. However, the FP-ε-SVR using ε-SVR is not very successful in identifying outliers. In this article, we propose an alternative method to detect outliers i.e. by employing nu-SVR. The merit of our proposed method is confirmed by three real examples and the Monte Carlo simulation. The results show that our proposed nu-SVR method is very successful in identifying outliers under a variety of situations, and with less computational running time

Harmonics Temporal Profile in High-Voltage Networks: Case Study

This chapter presents a case study about harmonics measurements in high-voltage networks. Measurements were conducted at two locations in the main interconnected system (MIS) of Oman. Voltage and current THDs were recorded for a period of 1 week. The power quality analyzer was set to record required data for a period of 1 week, and the observation period for each recorded value is 10 minutes. At the first location, the grid station (132/33) is feeding industrial as well as other customers. The second grid station (220/132/33 kV) is dedicated to large industrial customers including arc furnaces and rolling mills. The power quality analyzer was installed at the 132 kV side of power transformers at both locations. Recorded data are analyzed, and temporal harmonics profiles are studied. A clear temporal variation of harmonics similar to that of aggregate load and local voltage profiles was observed at the grid station feeding mixed residential and industrial loads. However, this correlation between system load and harmonics profile diminishes at the grid station dedicated for heavy industrial loads

Board characteristics and real performance in Malaysian state-owned enterprises (SOEs)

Purpose The purpose of this paper is to investigate the relationship between board characteristics and real performance among state-owned enterprises (SOEs) in Malaysia in a longitudinal period following the introduction of transformation policy. Design/methodology/approach The study deviates from prior research in utilising a real performance measure rather than traditional measures of performance. The authors adopt the quantile regression approach to examine the impact of board characteristics on real performance in a comparison using ordinary least squares. Findings The results of quantile regression reveal that the impact of board mechanisms on real performance was not as expected. Specifically, board size and duality had a bearing on real performance. Board independence also is considered as influential factor through the time. However, such effects were not homogenous across different quantiles. The dummy year variable to compare the period pre- and post-transformation policy reveals that the dummy year is not significant, indicating that performance post-transformation is indifferent compared to the pre-transformation policy period. Practical implications It is important for government to reconsider the policies embedded in the transformation policy. This study provides insights on the enhancement of board effectiveness and new developments regarding GLCs. Originality/value This is an early to attempt to measure real performance and its link to board characteristics in SOEs post-transformation policy

The optimum condition for the synthesis of carbon nanofibers on activated carbon to remove lead from aqueous solution

Optimum process condition for the production of Carbon Nanofibers (CNFs) to remove lead ion (Pb) from aqueous solution is reported here. The CNFs were produced on the catalyst (Ni2+) impregnated palm oil-based cheap Powder Activated Carbon (PAC). Locally fabricated Chemical Vapour Deposition (CVD) system was used while acetylene (C2H2) was the carbon source. The porous nano-composite product is named “PAC-CNFs”, which was synthesized through a process using impregnated oil palm shell based PAC as a solid substrate. Design Expert 6.0.8 software was used to design the experimental plan and to determine the optimized process parameters for the growth of CNFs by using sorption capacity for Pb2+ by the PAC-CNFs adsorbent, as a response. The effect of different factors on the growth of CNFs including the temperature of CNFs growth (550 to 750 °C), time of growth (30 to 60 min), and the ratio of input C2H2/H2 gases (0.25 to 1.0) was evaluated. The predicted values for the sorption capacity of Pb2+ by the PAC-CNFs were in close agreement with the experimental data (R2 = 0.99). The optimal process condition: temperature for the growth of CNFs, time, and C2H2/H2 ratio was determined as 637 °C, 30 min, and 1.0, respectively. The CNFs grown under the optimized condition exhibited sorption capacity of 77 mg/g in removing Pb2+ from synthetic wastewater containing lead (Pb2+) ion