Towards Energy Conservation in Qatar

Qatar energy consumptions are among the highest in the world, and can easily serve double the present population. Energy conservation is a must, as the energy resources are finite, and their consumptions are increasing at alarming rates. The country depends on desalted seawater, which consumes extensive amounts of energy, and is produced by using the least energy efficient desalting system. The desalination process is vulnerable to many factors, and strategic water storage needs to be built. The high energy consumptions are ruining the air and marine environments. Several suggestions are introduced to conserve energy in the Cogeneration Power Desalting Plants (CPDP), by moving to replace the Multi Stage Flash (MSF) desalting system by the energy efficient Seawater Reverse Osmosis System (SWRO);fully utilizing the installed power capacity to desalt water in winter, when electric power load is low, and during summer non-peak hours for strategic water storage;and modifying the simple Gas Turbines (GT) Power cycle plants to GT combined cycle to raise the Electric Power (EP) generation efficiency (to about 50%).

Prime Energy Challenges for Operating Power Plants in the GCC

There is a false notion of existing available, abundant, and long lasting fuel energy in the Gulf Cooperation Council (GCC) Countries;with continual income return from its exports. This is not true as the sustainability of this income is questionable. Energy problems started to appear, and can be intensified in coming years due to continuous growth of energy demands and consumptions. The demands already consume all produced Natural Gas (NG) in all GCC, except Qatar;and the NG is the needed fuel for Electric Power (EP) production. These countries have to import NG to run their EP plants. Fuel oil production can be locally consumed within two to three decades if the current rate of consumed energy prevails. The returns from selling the oil and natural gas are the main income to most of the GCC. While NG and oil can be used in EP plants, NG is cheaper, cleaner, and has less negative effects on the environment than fuel oil. Moreover, oil has much better usage than being burned in steam generators of steam power plants or combustion chambers of gas turbines. Introducing renewable energy or nuclear energy may be a necessity for the GCC to keep the flow of their main income from exporting oil. This paper reviews the GCC productions and consumptions of the prime energy (fuel oil and NG) and their role in electric power production. The paper shows that, NG should be the only fossil fuel used to run the power plants in the GCC. It also shows that the all GCC except Qatar, have to import NG. They should diversify the prime energy used in power plants;and consider alternative energy such as nuclear and renewable energy, (solar and wind) energy.

Toward Implementing HH the Amir Declaration of 2% Electricity Generation by Solar Energy in 2020

The utility solar power plants were reviewed and classified by two basic groups: direct thermal concentrating solar power (CSP) and photovoltaic (PV). CSP as Parabolic Trough Collector (PTC) of 100 MW solar power plants (SPP) is suggested and suitable to provide solar thermal power for Qatar. Although, LFC had enough experience for small projects, it is still need to work in large scale plant such as 100 MW and couple with multi effect distillation (MED) to confirm costs.

Rational Design of Titanium Carbide MXene Electrode Architectures for Hybrid Capacitive Deionization

Intercalation redox materials have shown great promise for efficient water desalination due to available faradaic gallery sites.Symmetric capacitive deionization(CDI)cells previously demonstrated using MXenes were often limited in their salt adsorption capacity(SAC)and voltage window of operation.In this study,current collector-and binder-free Ti3C2Tx MXene electrode architectures are designed with porous carbon as the positive electrode to demonstrate hybrid CDI(HCDI)operation.Furthermore,MXene current collectors are fabricated by employing a scalable doctor blade coating technique and subsequently spray coating a layer of a small flake MXene dispersion.Hydrophilic redox-active galleries of MXenes are capable of intercalating a variety of aqueous cations including Na+,K+,and Mg2+ions,showing volumetric capacitances up to 250 F cm-3.As a result,a salt removal capacity of 39 mg g-1 with decent cycling stability is achieved.This study opens new avenues for developing freestanding,binder-and additivefree MXene electrodes for HCDI applications.

Are assemblages of the fireworm Hermodice carunculata enhanced in sediments beneath offshore fish cages?

Abundances of the fireworm Hermodice carunculata were counted through a monitoring assessment study of fish cages in Barranco Hondo（NE Tenerife）. Seven campaigns were conducted from November 2007 to June 2010 and temporal variations were found, as well as differences among sampling stations. The polychaete H. carunculata obtained its highest abundance in sediments beneath fish cages throughout the study period. Thus, the assemblages of this omnivorous species were favoured by the presence of fish cages.

Error Analysis of the Density-Matrix Renormalization Group Algorithm for a Chain of Harmonic Oscillators

我们调查密度矩阵重正常化组(DMRG ) 的应用程序算法到一个一个维的泛音振荡器与准确解决方案锁住并且比较结果，瞄准改进算法的效率。算法能看相当精确的结果过程是否适当地被组织，这被表明；例如，由使用优化的底。计算地面状态精力和精力的错误在扎根的状态和第一个激动的状态之间豁开被分析，并且他们被发现极其依赖于系统的尺寸或学习系统的精力水平结构和在 DMRG 过程期间指向的状态的数字。

Effect of Optical Radiation on the Properties of Gamma Radiated Silicate Glass

We study the effect of intense laser radiation on the surface of silicate glass prior irradiated by gamma radiation. Experimental results show that the gamma radiation with dose 5 × 104 R leads to the degradation of the surface resistance of this optical dielectric to electromagnetic radiation. Depending on the dose of the radiation the laser radiation can result in either surface erosion or its pronounced cracking. It is also found that the efficiency of the degradation process is determined not only by the radiation dose, but also by the presence of different impurities in the glass.

Biochar from vegetable wastes:agro-environmental characterization

Considering the global issue of vegetable wastes generation and its impact on the environment and resources,this study evalu-ated the conversion of four largely produced vegetable wastes(cauliflower,cabbage,banana peels and corn cob residues)into biochar.Each waste was tested individually and as a combined blend to assess feedstock influences on biochar properties.In addition,various pyrolysis temperatures ranging from 300℃ to 600℃ and two particle size fractions(less than 75μm,75-125μm)were considered.Biochars were characterized for various properties that can influence the biochars’effective-ness as a soil amendment.It was found that pyrolysis temperature was the most dominant factor on biochar properties,but that individual feedstocks produced biochars with different characteristics.The biochars had characteristics that varied as follows:pH 7.2-11.6,ECE 0.15-1.00 mS cm^(−1),CEC 17-cmolc kg^(−1)andζ-potential−0.24 to−43 mV.Based on optimal values of these parameters from the literature,cauliflower and banana peels were determined to be the best feedstocks,though mixed vegetable waste also produced good characteristics.The optimum temperature for pyrolysis was around 400℃,but differed slightly(300-500℃)depending on the distinct feedstock.However,smaller particle size of biochar application was always optimal.Biochar yields were in the range of 20-30%at this temperature range,except for corn cobs which were higher.This study demonstrates that pyrolysis of dried vegetable wastes is a suitable waste valorization approach to produce biochar with good agricultural properties.

An efficient descriptor model for designing materials for solar cells

An efficient descriptor model for fast screening of potential materials for solar cell applications is presented.It works for both excitonic and non-excitonic solar cells materials,and in addition to the energy gap it includes the absorption spectrum(α(E))of the material.The charge transport properties of the explored materials are modelled using the characteristic diffusion length(Ld)determined for the respective family of compounds.The presented model surpasses the widely used Scharber model developed for bulk heterojunction solar cells.Using published experimental data,we show that the presented model is more accurate in predicting the achievable efficiencies.To model both excitonic and non-excitonic systems,two different sets of parameters are used to account for the different modes of operation.The analysis of the presented descriptor model clearly shows the benefit of includingα(E)and Ld in view of improved screening results.