50 research outputs found
Riesz basis property of weak eigenfunctions for boundary-value problem with discontinuities at two interior points
No full textInternational Conference on Advances in Natural and Applied Sciences (ICANAS) -- APR 18-21, 2017 -- Antalya, TURKEYWOS: 000405093100032We investigate one discontinuous boundary value problem which consist of a Sturm-Liouville equation with piecewise continuous potential together with eigenparameter-dependent boundary conditions and four supplementary transmission conditions. We establish some spectral properties of the considered problem. For the problem under consideration we define a new concept so-called weak eigenfunctions which is an extension of a classical eigenfunction and prove that the system of weak eigenfunctions form a Riesz basis of the appropriate Hilbert space for the modified Lebesgue space.Agri Ibrahim Cecen Univ, IC Fd
Multi-point transmission problems for Sturm-Liouville equation with an abstract linear operator
No full textInternational Conference on Advances in Natural and Applied Sciences (ICANAS) -- APR 18-21, 2017 -- Antalya, TURKEYWOS: 000405093100022In this paper, we consider the spectral problem for the equation -u ''(x) + (A + lambda I)u(x) = f(x) on the two disjoint intervals (-1, 0) and (0, 1) together with multi-point boundary conditions and supplementary transmission conditions at the point of interaction x = 0, where A is an abstract linear operator. So, our problem is not a pure differential boundary-value one. Starting with the analysis of the principal part of the problem, the coercive estimates, the Fredholmness and isomorphism are established for the main problem. The obtained results are new even in the case of boundary conditions without internal points.Agri Ibrahim Cecen Univ, IC Fd
The role of Islam and natural resources in current Mali political turmoil
No full textIn the recent times, the Republic of Mali has been striving to restore peace and harmony in the state. The conflict initiated by
insurgent Islamist groups fighting against the Malian government for independence in northern Mali. The revolt against the
government is associated with the implementation of shariah laws. Despite the current decrepit political condition in Mali it
seems to be a site of attraction of Western military intervention. This paper studies the role of religion and natural resources in
the conflict. Mali is one of the poorest countries in the world but in reserve it has one of the largest amounts of mineral
deposits including uranium and other energy related resources. The significance of this paper is that it critically analyses the
legality, motives and purpose of French intervention in Malian conflict and direct US support for it
Timbuktu civilization and its significance in Islamic history
No full textTimbuktu civilization began as a seasonal settlement for trade caravans in the early 11th century. It later flourished in trade and
as one of the early African centres of Islamic culture. This paper reviews the trend of Timbuktu civilization from prehistoric
period up to the current state of its political impact of the region. The paper further focuses on the role Timbuktu played in
African history by serving as academic and commercial centre. The significant of this paper is to reveal the fact that Africa has
a long Islamic civilization. The paper provides evidences from reliable sources of the symbolic representation of the impact and
influence of the early schools and universities between 11th and 15th century that existed in West Africa. The manuscript of
Timbuktu serves as a living testimony of the highly advanced and refined civilization in Africa during the middle ages. The
history of monuments, artefacts as well as architectural land marks that signifies the historical origin of this ancient city is
presented. The early heroes that stood firm towards the development and civilisation of Timbuktu are outlined. Analysis of the
development as well as the factors that led to the civilization is presented in this paper
A piezoelectric based energy harvester with magnetic interactions: modelling and simulation
No full textIn recent years, utilizing kinetic energy in mechanical vibrations has become an interesting area of research. This is due to ubiquitous sources of vibration energy, coupled with the ever increasing demands to power wireless sensing electronics and Microelectromechanical (MEMs) devices with low energy requirements. Thus, researchers have ventured into developing different system configurations with the aim of harvesting vibration energy to power these devices.
Cantilever beam systems with piezoelectric layer have been used as vibration energy scavengers due to their abilities of converting kinetic energy in vibrating bodies into electrical energy, whereas permanent magnets have been used to improve their performance. The only unresolved challenge is to develop energy harvesters that can produce optimum energy at a wider bandwidth. In this study, a mathematical model of a system of cantilever beams with piezoelectric layers having a magnetic coupled tip mass is proposed. The lumped parameter model of the harvester is developed to estimate the power output of the proposed harvester, and to visualise the effect of magnetic coupled
tip mass in widening the frequency bandwidth of the energy harvester. Preliminary Simulation results using MATLAB have however shown the effectiveness of the proposed system
Piezoelectric based vibration energy harvester with tip attraction magnetic force: modeling and simulation
No full textIn recent times, vibration based energy harvesting
has drawn attention of many researchers worldwide. This is due to advancement in Microelectromechanical (MEM) devices and wireless sensors with power requirements in range of microwatts-milliWatts; hence vibration energy sources have promising potentials for such demands. Thus, many attempts were made by researchers to develop different system configurations for effective utilization of vibrations that happen all around us. Cantilever beams with piezoelectric
patches are used to harness kinetic energy from mechanical vibrations. This paper is aimed at studying the effect of adding a magnetic force at the tip mass, which is also a magnet with opposite pole, on power output of the energy harvester. The additional attraction force between the tip mass and the fixed magnet influences stiffness of the system, whilst tuning the natural frequency. Mathematical equation to depict the
relationship between tuned natural frequency and distance between permanent magnet is derived. The lumped parameter model for the harvester with single fixed magnets aligned with magnetic tip mass is derived. MATLAB software is used to perform the simulation study on influence of the magnet on the harvester
The role of the accused in English and Islamic criminal justice
No full textThis thesis is a comparative study of the role of the accused in the systems of
English and Islamic criminal justice. It seeks to explore the underlying
relationship between the individual and the state through an historical, structural
and contextual analysis of their rules relating to questioning and of confessions.
The analysis of the English system covers the period 1800 to 1984, with
particular reference to developments during the nineteenth century when the
foundations for the modern English state were established. The analysis of the
Islamic system combines traditionally Islamic and modern methods, assessing the
"Islamisation" movement in Malaysia through a religico-structural understanding
of juristic opinion from the four main schools of Sunnite jurisprudence.
The thesis contributes to existing knowledge on a number of levels: first, it
questions and revises the "myth" of "progress" that has dominated observations
of the history of the English criminal justice system; second, it elucidates the
relationship between Islamic law in theory and the law that is applied and
proposed in its name in Muslim states; third, it provides an analytical framework
for drawing comparisons between the underlying values of the systems of English
and Islamic criminal justice.
While acknowledging fundamental differences in terms of outlook and
articulation, the author concludes there are important similarities expressed
through such notions as "suspect" in the English system and "kafir"I"fasiq" in the
Islamic. These act as intermediate constitutional categories to whom the state
owe less protection. But the author notes also that these similarities are not
observed necessarily in the "law" which is implemented or proposed in Muslim
states; exact correspondence depends upon the over-arching political structure
and the institution of Caliphate.
The thesis is divided into six chapters: chapter one sets out the conventional view
of the historical development of English criminal procedure and evidence;
chapter two subjects that to a critique and chapter three offers a revised thesis.
Chapter four, explores methods for interpreting and explaining Islam; chapter
five sets out rules relating to confessions and questioning according to the four
Sunni schools; chapter six puts them into "context" through an examination of
the "Islamisation" process in Malaysia
A review on recent advances of CNTs as gas sensors
No full textPurpose - This review paper aims to focus on recent advances of carbon nanotubes (CNTs) to produce gas sensors. Gas sensors are widely used for monitoring hazardous gas leakages and emissions in the industry, households and other areas. For better safety and a healthy environment, it is highly desirable to have gas sensors with higher accuracy and enhanced sensing features. Design/methodology/approach - In this review, the authors focus on recent contributions of CNTs to the technology for developing different types of gas sensors. The design, fabrication process and sensing mechanism of each gas sensor are summarized, together with their advantages and disadvantages. Findings - Nowadays, CNTs are well-known materials which have attracted a significant amount of attention owing to their excellent electrical, electronic and mechanical properties. On exposure to various gases, their properties allow the detection of gases using different methods. Therefore, over recent years, researchers have developed several different types of gas sensors along with other types of sensors for temperature, strain, pressure, etc. Originality/value - The main purpose of this review is to introduce CNTs as candidates for future research in the field of gas sensing applications and to focus on current technical challenges associated with CNT-based gas sensors
Neobuthus awashensis Kovarik & Lowe 2012
No full textNeobuthus awashensis Kovařík & Lowe, 2012 (Figs. 55–56, 403, 418, 421, 438, Table 5) Neobuthus awashensis Kovařík & Lowe, 2012: 7–16, figs. 5–6, 18–21, 34–38, 44–47, 67–74, 86, 89, 92, 95–96, 100–101; Kovařík et al., 2015: 30; Lowe & Kovařík, 2016: 2–4, figs. 1–6, 158, 161–165. TYPE LOCALITY AND TYPE REPOSITORY. Ethiopia, Awash, Metahara env., 08°54'N 39°54'E, 960-1050 m a.s.l., FKCP. TYPE MATERIAL EXAMINED. Ethiopia, Awash, Metahara env., 08°54'N 39°54'E, 960-1050 m a.s.l., 1♀ (paratype), 2008, leg. V. Trailin, 2♀1♀ im. (allotype and paratypes), XI.2010, leg. T. Mazuch and P. Novák, 32♂ (holotype and paratypes) 18♀ (paratypes) 11♀ ims, 5♂ ims (paratypes), 19.-22.VII.2011, leg. F. Kovařík. Most types including holotype are in the collection of the first author (FKCP), other paratypes are in the GLPC, MRAC, RTOC, ZMHB, and ZMUH collections. OTHER MATERIAL EXAMINED. Ethiopia, 11°43'22"N 40° 56'52"E, 457 m a.s.l. (Locality No. 12 EMA), 20.XI. 2012, 1♀1♀ im., leg. F. Kovařík (UV detection), FKCP; 11°43'30"N 40°58'45"E, 404 m a.s.l. (Locality No. 12EM), 20.XI.2012, 1♂, leg. F. Kovařík (UV detection), FKCP; Gewane, 10°09'38"N 40°39'45"E, 631 m a.s.l. (Locality No. 12 EO), 23.XI.2012, 1♂ 1♀, leg. F. Kovařík, (UV detection), FKCP; 09°08'10.4"N 40° 09'45.5"E, 835 m a.s.l. (Locality No. 12ER), 24.XI. 2012, 12♂ 1♀ 1juv., leg. F. Kovařík (UV detection), FKCP, 26.-27.XI.2014, 8♂ 2♀ 2juvs, leg. F. Kovařík, FKCP; Awash, Metahara env., 08°54'N 39° 54'E, 960- 1050 m a.s.l. (Locality No. 12 EX), 25.XI. 2012, 7♂ 6♀ 5juvs., 27.-30.XI.2014, 7♂ 1♀ (Figs. 55–56), topotypes, leg. F. Kovařík (UV detection). DIAGNOSIS. Total length 18–22 mm (males), 22.5–30 mm (females); carapace with area between anterior median carinae fuscous; tergites with fuscous pigmentation unbroken across median area; pedipalp relatively slender, males with femur L/ W 2.50 –2.70, patella L/ W 2.45 –2.70, chela L/ W 4.63 –5.08; chela movable finger with 5–6 subrows of primary denticles, 3–5 external accessory denticles flanking proximal end of each subrow; trichobothria d 2 usually absent from femur and patella; dorsoexternal and ventroexternal carinae on pedipalp patella in female well developed; posterior margins of tergites with 1–2 pairs of macrosetae; pedipalps, legs, metasoma and telson with short, stout macrosetae in males, and long, fine setae in females; males with coxae sparsely granulated, sternites III–VI lightly shagreened to smooth, sternite VII finely granulated with 4 weak, granulated carinae; females with sternites III–VI smooth, sternite VII sparsely shagreened with 4 weak carinae, median carinae granulated; metasoma I–III with median lateral carinae present in both sexes; lateral surface of metasoma V in males densely granulated, with granules separated; soles of telotarsi with relatively sparse setation, leg III of adults with 12–19 ventral macrosetae on telotarsus; pectine teeth: 17–21 (males), 15–18 (females).Published as part of Kovařík, František, Lowe, Graeme, Awale, Ahmed Ibrahim, Elmi, Hassan Sh Abdirahman & Abdi, Ali, 2018, Scorpions of the Horn of Africa (Arachnida, Scorpiones). Part XVII. Revision of Neobuthus, with description of seven new species from Ethiopia, Kenya and Somaliland (Buthidae), pp. 1-82 in Euscorpius 271 on page 1
Comparative study of conventional and magnetically coupled piezoelectric energy harvester to optimize output voltage and bandwidth
No full textEnergy harvesting has experienced significant
attention from researchers globally. This is due to the quest to power remote sensors and portable devices with power requirements of tens to hundreds of μW. Hence, ambient vibration energy has the potential to provide such power demands. Thus, cantilever beams with piezoelectric materials have been utilized to transduce mechanical energy in vibrating bodies to electrical energy. However, the challenge is to develop energy harvesters that can harvest sufficient amount of energy needed to power wireless sensor
nodes at wide frequency bandwidth. In this article, piezo-
electric energy harvester (PEH) beams with coupled mag-
nets are proposed to address this issue. With macro fiber composite as the piezoelectric transducer, mathematical models of different system configurations having magnetic couplings are derived based on the continuum based model. Simulations of the system dynamics are done using numerical integration technique in MATLAB software to study the influence of magnetic interactions in generating power and frequency bandwidth due to base excitations at low frequency range. Experimental results comparing conventional system and the proposed piezoelectric beam configurations with coupled magnets are also presented. Finally, the optimal beam separation distance between the magnetic oscillator and PEH is presented in this work
