Dome Type Research Articles

Teknologi Produksi Biogas dari Limbah Ternak untuk Memenuhi Kebutuhan Energi Rumah Tangga

Limbah ternak dapat menurunkan kualitas lingkungan apabila tidak dikelola dengan baik, dilain pihak limbah ternak dapat diolah menjadi sumber energi yang dapat dimanfaatkan oleh rumah tangga. Limbah ternak diolah menjadi biogas dengan proses fermentasi anaerobik. Biogas adalah salah satu energi terbarukan dan ramah lingkungan. Energi biogas dapat diperoleh dari air buangan rumah tangga; kotoran cair dari peternakan ayam, sapi, babi; sampah organik dari pasar; industri makanan dan sebagainya. Untuk mengubah limbah ternak menjadi biogas dibutuhkan serangkaian alat yang disebut reaktor biogas. Penggunaan sistem reaktor biogas memiliki keuntungan, antara lain yaitu mengurangi efek gas rumah kaca, mengurangi bau yang tidak sedap, mencegah penyebaran penyakit, panas, daya (mekanis/listrik) dan hasil samping berupa pupuk padat dan cair. Reaktor biogas terbagi menjadi tiga tipe yaitu tipe terapung, tipe kubah tetap, dan tipe balon. Tipe reaktor biogas yang direkomendasikan untuk pengolahan biogas limbah ternak adalah reaktor tipe kubah tetap (fixed dome) karena memiliki keunggulan diantaranya adalah biaya konstruksi lebih murah daripada reaktor terapung, bisa dikerjakan sendiri oleh peternak, lebih tahan lama dibanding reaktor tipe balon, serta perawatannya lebih mudah.

Correction of posttraumatic deformities of the distal tibia with focal dome osteotomy

Supramalleolar deformities require surgical correction to avoid posttraumatic osteoarthrosis of the knee or ankle joint and to prevent definitive treatment options, such as total ankle arthroplasty or arthrodesis of the ankle joint. Various methods for the operative correction of supramalleolar deformities have been described in the literature. What results can be achieved with focal dome osteotomy to correct posttraumatic supramalleolar deformities? A total of 10 patients (mean age 37years) with asupramalleolar posttraumatic deformity were treated by focal dome osteotomy. The mean follow-up was 27months (min.6, max. 105 months), 5 patients were female and 5 male. The supramalleolar varus/valgus deformity was on average 20° (at least 12°, maximum 33°). Preoperative and postoperative mechanical axis and joint angles were determined on digital radiographs. The American Orthopedic Foot and Ankle Society (AOFAS) score was used to assess the clinical outcome. In seven patients the anatomical leg axis could be restored. In three patients aresidual deformity of 2.8° was observed. Bone grafting was not necessary in any of the cases. Of the patients eight had free ankle mobility and two showed an average movement limit of 30° compared to the contralateral side. Posttraumatic ankle arthrosis was not observed in the short-term and medium-term results. The mean AOFAS score of 80points (minimum70, maximum98) documented afunctionally good result. Supramalleolar dome type osteotomy is atechnically difficult method for acute correction of supramalleolar deformities. The functional results and complication rates are comparable to those in the literature for alternative osteotomy techniques.

Survey of the Outer-Shell Structure of the Double-Shell Discrete Nar Domes

ABSTRACTIt is assumed that the geometric form of the outer shell of a dome has an effect on the dome’s structural performance. By mathematical drawing of the arch forms used for different types of dome, it is possible to calculate their structural behaviour under different circumstances. It appears that each form of arch has different visual and structural effects and features, as well as different material requirements. The most distinctive arch, that is, Sarvak, represents very different behaviour from the other arch forms. Furthermore, variation of the thickness of the dome at higher levels has dramatic effects on level of structural stability.

Dynamics of a group of quasi-zero stiffness vibration isolators with slightly different parameters

This article is devoted to finding solutions of problems of vibration isolators with quasi-zero stiffness from a manufacturing point of view. The following study is appeared after experimental study and manufacturing of preproduction serial of universal isolators of a dome type. An analytical description of some types of vibration isolators with quasi-zero stiffness is briefly observed. The sensitivity of vibration isolators of a dome type is studied. It is proved that vibration isolators with quasi-zero stiffness require high precision at manufacturing. Dynamics of a group of vibration isolators is also analyzed. It appears that an average behavior of an isolator in a group may not coincide with the behavior of a single isolator. Due to the normal distribution of parameter, the total properties of the vibration isolator can be slightly changed.

Fault-related domes: Insights from sedimentary outcrops at the northern tip of the Gulf of Suez rift, Egypt

Domes may develop with various mechanisms in different types of rocks. Knowing the geometries and occurrences of domes is an important concern in classifying different types of domes. A number of fault-related domal structures are outcropped at the northern Gulf of Suez rift, Egypt and they are easily visualized on satellite imagery. Detailed surface geological field mapping is carried out at several localities to assess types and origins of these domes. Three main subdivisions of fault-related domes are suggested in the present study. These are: (1) domes formed in strike-slip zones (D-SZ), (2) domes formed by drag along normal fault arrays (D-DF) and (3) domes formed at transfer zones of normal faults (D-TZ). Structural analysis of the studied domes reveals that each dome type has its own geometric parameters, structural style and tectonic setting. The obtained results are without doubt interesting for the analysis of similar domes at the subsurface and other exposures worldwide.

Большепролетные металлические купольные покрытия и их возведение

The article presents the main types of geometrical and structural systems of steel frameworks of metal dome roofs. Based on the geometrical system, three main types of metal domes can be specified: ribbed domes, ribbed domes with rings, and lattice domes. Lattice domes can be cyclically symmetrical with repeating sectorial patterns, or geodesic, that are based on geodesic polyhedrons, inscribed in a sphere. Based on the structural system, the frameworks of ribbed domes can have single chord or dou- ble chord ribs. Geometric system of the framework of a large-span metal dome governs the method of its erection which in its turn defines the structural solutions for the elements of the framework and the sequence of their assembly. The paper describes the following methods of erection of large-span domes: erection by crane from the ground with temporary supports, placement of the complete structure or large elements of the dome, and cantilever erection. The examples of large-span metal domes built in different countries of the world are reviewed with respect to the method of construction used. General characteristics of the structural system of the framework of each dome are presented. The examples are used to demonstrate that the method of construction of a large-span metal dome roof is dependent on the geometric system of its framework. It is noted that metal domes are widely used as structural solutions for roofs of buildings of different types. It is noted that erection with temporary supports of different types, or ground assembly are mostly used for the construction of relatively low double layer domes, or high single-layer domes. For large-span double-layer metal domes of considerable high the method of cantilever erection is usually preferred.

Vibration isolating plate with quasi-zero effect

The Paper is devoted to vibrating isolating plate with quasi-zero stiffness. It based on dome type cells with quasi-zero stiffness, that provide low natural frequency about 1 Hz. The general scheme of the plate is presented. Dimension, efficiency and other parameters of the plate were discussed. The effect of plate's application has been estimated. The plate allows to reduce vibration level. It also allows to reduce size of foundation of machines almost two times.

COMPARISON BETWEEN LOCATER AND MAGNETIC ATTACHMENT SYSTEMS FOR SINGLE IMPLANT RETAINED MANDIBULAR OVERDENTURE (STRAIN GAUGE ANALYSIS)

Objective: the aim of this study was to compare stresses induced in locater and magnetic dome type attachments for single implant retained mandibular overdenture by using strain gauge analysis.Material and methods: One clear acrylic model was constructed representing completely edentulous lower ridge. A single implant was placed in the midline region of this model and two identical experimental overdentures were constructed. The first overdenture was fitted to single implant through a locater attachment while the second was fitted to implant through a Magnet Dome attachment. Four strain gauges were installed in labial and lingual surfaces and the right &left sides of single midline implant. A special loading device (universal testing machine) was used to apply standardized static vertical load with a magnitude of 100 N at the right first molar tooth on the occlusal surface of each experimental overdenture.Results: Comparing the two attachments that were studied, the differences were statistically significant, independent T test showed significant difference between Locater and Magnetic attachment groups. Conclusions: Within the limitation of this study, it could be concluded that: magnetic attachment induce less stresses than locater attachment in case of single implant retained mandibular overdenture.

Cúpulas de barro, de piedra y de barro y piedra en las construcciones auxiliares de la arquitectura popular del centro de Castilla y León

En el centro de Castilla y León todavía existen algunos ejemplos de antiguas construcciones rurales vinculadas a las actividades económicas del mundo agrario. Conocidas como chozos y casetas, se cubrieron con soluciones cupuliformes empleándose los materiales que más a mano se tenían, siendo el barro y la piedra los más comunes. Las técnicas constructivas tradicionales en ambos elementos generaron un abanico tipológico singular, poco común en el resto de la península y digno de estudio. Gracias a un extenso trabajo de campo se han identificado, inventariado y clasificado una amplia variedad de tipos constructivos cupuliformes, que se han contrastado con fuentes documentales, ampliando significativamente la información publicada que se tenía de ellas, especialmente de su variedad y proceso constructivo. Esta investigación pretende proporcionar herramientas para valorar y recuperar un conocimiento constructivo que ya está olvidado, resaltando su riqueza arquitectónica, para fomentar su conservación e incluso la recuperación en algunos casos.

Effect of co-digestion agricultural-industrial residues: various slurry temperatures

ABSTRACTThe main objective of this study is to investigate the effect of co-digestion using industrial-agro waste and operating temperature of digester slurry to enhance the biogas and methane yield. The anaerobic digestion process is carried out by using a floating dome type bio-digester with the capacity of 1 m3. The co-digestion of press mud and rice straw with the ratio of 1:1, slurry temperature mesophilic range of (30–40°C) and thermophilic raange of (41–55°C) is used in this study. The maximum generation of daily biogas and weekly methane yield obtained were about 190 L/day and 55% in the case of the thermophilic condition. The lowest generation of daily biogas and weekly methane yield obtained were about 130 L/day and 33% in the case of mesophilic condition. The 10 percentage of cow dung is used as an inoculum of the digester and 30 days of hydro retention time for both the temperature ranges. The methane and biogas yield is at its peak and there was a faster hydro retention time in thermophilic range temperature at 52°C.

Corrosion failure analysis of hearing aid battery-spring contacts

Abstract Reliability of low power electrical contacts such as those in hearing aid battery-spring systems is a very critical aspect for the overall performance of the device. These systems are exposed to certain harsh environments like high humidity and elevated temperatures, and often in combination with high levels of salt from human perspiration and environmental pollutants. In addition, the design aspects of such systems often call for multi-material combinations of substrate and coatings for catering to various requirements such as electrical conductivity and wear resistance, which in turn enhance the susceptibility of these systems to galvanic corrosion. In this study, traditional behind-the-ear (BTE) hearing aid systems, which failed during service were analysed. Failure analysis was performed on the dome type battery-spring contact systems. The morphology of the contact areas was observed using scanning electron microscopy, and the compositional analysis of the corrosion products and contaminants was performed using energy dispersive X-ray spectroscopy. Wear track morphology was observed on the contact points, and the top coating on the dome was worn out exposing the substrate spring material. The obtained results were correlated to the underlying corrosion mechanism and the failure mode is presented.

Design and development of portable household biogas plant

Energy is one of the prerequisites for the growth of agriculture and industry. The growing global awareness of the energy crises has brought us to the beginning of what might be called as the recycle revolution. Biogas as an alternative source of energy has been widely recognized in a number of countries of the various alternative sources of energy. Biogas energy assumes a major role with special reference to the rural sector. Biogas is generated by anaerobic digestion using cow dung, methane content of the gas produced from the digestion of the cattle varied from 60 to 72 per cent, the remaining being carbon-dioxide. The feed material cow dung and kitchen waste selected for experimental study was analyzed for physical and chemical characteristics using standard procedure. A cylindrical shaped floating drum type biogas plant which gives constant gas pressure, less scum problem, higher gas production per cubic meter of digester volume and less leakage over fixed dome type plant. The biogas digesters work safely up to a pressure range of 0.05 kg/cm 2 (50 m bar). Hence, the pilot size biogas plant designed will operate safely. The pressure developed inside the gas holder was measured by using the Borden type pressure gauge (0-2 kg/cm 2 ). The temperature of gas was measured by handheld thermometer (0-110° C). The cow dung, kitchen waste and water is mixed in definite proportions on weight basis to bring the total solid. The amount of gas produced in 24 hours was measured daily from gas holder till 40 days of experiment. The experimental result indicated that 6 to 8 per cent of digester volume added with inoculums before feeding the material increased the biogas production. It was noted that combination gas production from slurry combination was 350.99 liters in 2.08 size digester at the end of retention period of 56 days.

Gneiss domes of the Danba Metamorphic Complex, Songpan Ganze, eastern Tibet

In this paper we address the formation and exhumation of the Danba Metamorphic Complex (DMC) that represents the deepest structural level of the Songpan Ganze terrane situated along the eastern margin of the Tibetan plateau. The DMC comprises a variety of gneiss domes and offers a unique opportunity to decipher their development during orogenic evolution. For that purpose, PTtD paths of metamorphic rocks sampled at different structural levels have been reconstructed. The DMC is composed of Triassic metaturbidites of the Xikang group, Paleozoic metasedimentary cover and basement of the Yangtze craton. The DMC is structurally marked by transposition of the upright S1 foliation of the Triassic metaturbidites into a NW-SE trending S2 composite foliation dipping to the NE. Transposition is associated with a localized top-to-the-northeast shear zone along the northeastern edge of the DMC and with pervasive top-to-the-southwest shearing from the core to the border of the complex. These structures are consistent with extrusion of the core of the DMC relative to the lower grade Triassic metaturbidites. The position of the biotite isograd overlapping the structural boundary of the DMC suggests that the Triassic metaturbidites have been affected by an increase in temperature as a result of extrusion. Within the DMC, the position of the metamorphic index minerals relative to the composite S2 foliation reveals that biotite, garnet, staurolite and kyanite grew before the transposition into S2, in contrast with sillimanite which crystallizes in the hinge of F2 folds and along the axial planar S2 schistosity. The sillimanite isograd delineates regional-scale overturned F2 folds and cross-cuts the staurolite and kyanite isograds consistent with an increase in temperature during D2. The melt-in isograd characterizes the deepest structural level of the DMC. PT conditions for these metamorphic rocks, determined using pseudosections and conventional thermometry, indicate a temperature increase from 400°C to more than 600°C from the edge to the core of the DMC for a relatively homogeneous pressure ranging from 5 to 6.5kbar suggesting that isograds and isotherms represent the syn-D2 thermal structure of the orogenic crust. Migmatites exposed in the deepest structural level of the DMC yield a pressure significantly lower than the surrounding metamorphic rock suggesting that they crystallized after D2 and after some exhumation of their hosts. Three different types of gneiss domes are distinguished on the basis of their position relative to the isograds, their structural characteristics, and their position relative to the margin of the Yangtze craton. Close to the craton and at the highest structural level, the Gezong dome represents a basement-rooted tectonic slice, in an intermediate position, the Gongcai dome corresponds to a basement-cored nappe, and further away and at the deepest structural level, the Bawang, Cunuchan and Qingaling domes are migmatite-cored domes. The presence at the current-day surface of this variety of gneiss domes reflects the difference in burial of the margin during the Mesozoic Indosinian orogeny.

Performance and Analysis of Floating dome Anaerobic Digester with Wet and Dry Feedstock

The objective of this study is to evaluate the feasibility of anaerobic digestion to generate biogas yield and it’s performed using wet and dry feed stock. The laboratory experiment is conducted in a floating dome type anaerobic digester with 1m3 capacity. It is made up of fibre material at continues process. The starter cowdung used as an inoculum of the anaerobic digester. Then raw materials feeded as a wet type wheat straw and dry type wheat straw is the ratio of 1:1 waste/water in both the experiments wet and dry wheat straw. In this experiments are fermented at 30ºC to 35ºC temperature is maintained. The daily biogas yield, cumulative biogas yield, pH, CH4, and hydro retention time these parameters is studied and analysed. The maximum daily biogas is 25liters and 42% of methane is achieved in dry wheat straw at 15th day of digestion. The highest gas yield obtained in dry condition compare to wet condition and acid level also decreased in wet digestion.

Copper and Gold Mineralization Features in Deh Bala Region—South of Takestan

The studied area is located in 30th km of Bouien-Zahra road in Saveh in southern border of Khiaraj 1:100,000 Geology map rectangle (Danesfahan) in South of Takestan of Iran. This area is a part of volcano-plutonic belt of Urumia-Dokhtar. Rocky outcrops in this area are mainly in two types of volcanic and plutonic. Volcanic Rocks with the age of Eocene are Trachyte to trachyandesite and andesite to basalt-andesite. Plutonic stones with the age of Oligo-Miocene to Miocene are in types of quartz diorite, quartz monzonite, Monzonite and Semi-acidic volcanic domes and granite aplite. Due to having dominant fault systems with trends of NW-SE and NE-SW in an intersectional manner in this area, vein-veinlets Siliciclastic sulfide mineralization can be observed in line with the same faults. Monzonite intrusive rocks are considered as host stone of these mineralizations. The information obtained from field observations and laboratory studies confirms the main alteration along with mineralization in types of silicic and pyrite, sericite, carbonate, argillic and propylitic. Mineralogy Paragenesis in the study area includes Pyrite, chalcopyrite, bornite, colitis, malachite, hematite and goethite and the most important Gang minerals including quartz, calcite, albite, sericite, kaolinite, pyrophyllite, epidote, alunite and jarosite, and according to carried out studies, copper, gold and silver are among mineralizing elements and elements such as molybdenum, cadmium, arsenic and mercury show anomalies as accompanying and guidance elements in some of the samples. The grade of copper in this area in sulfide siliciclastic veins is 1% to 3% and the grade of gold is 130 ppm and the grade of silver is reportable from 0.5 ppm to 6 ppm. Based on the geothermometry studies of fluid inclusions, homogenization temperature from 150°C to 300°C and the salinity grade from 4 to 5.5 percent indicate the fact that an epithermal hydrothermal system in final stages controls the mineralization of the area.

비선형 과도해석을 이용한 스페이스 프레임 구조물의 동적특성

형태(from), 층(layer), 격자(grid) 등의 요소들이 고려되는 스페이스프레임 구조는 내부기둥 없이 대공간 연출이 가능하고, 대다수의 부재들이 210MPa에서 450MPa의 항복강도를 가진 강재들이 사용된다. 최근 국내에서 용접성과 내진성 및 경제성이 확보하고 제작 효율이 높은 항복강도 690MPa이상의 고강도 강재가 개발되고 있다. 본 연구는 스페이스 프레임 구조시스템에 위와 같은 장점을 가진 고강도 강재를 적용하여 구조물의 동적응답을 알아보기 위한 내용이며, 재료 및 기하학적 비선형성에 의한 스페이스 프레임의 구조적 성능을 해석적으로 규명하고자 한다. 이를 위해 각 형태에 따른 스페이스 프레임 구조물의 모드해석 및 비선형 과도해석 등의 유한요소 해석을 수행하였다. Space frame structures considering the components such as forms, layers, grids, etc. are possible to form a large space without interior columns. Here, steels having the yield strengths of 210 MPa to 450 MPa are generally used. The high strength steel (i.e., yield strength of 690 MPa) having suitable weldability, aseismicity and economics have been recently developed. In this paper, the high strength steel is applied to the space frame structures in order to analytically find out their transient responses considering the material and geometric nonlinearities. For various circular dome types of space frame structures, the modal analysis and nonlinear transient analysis are carried out using nonlinear three dimensional finite element analysis.

Two types of superconducting domes in unconventional superconductors

Uncovering the origin of unconventional superconductivity is often plagued by the overwhelming material diversity with varying normal and superconducting (SC) properties. In this article, we deliver a comprehensive study of the SC properties and phase diagrams using multiple tunings (such as disorder, pressure or magnetic field in addition to doping and vice versa) across several families of unconventional superconductors, including the copper-oxides, heavy-fermions, organics and the recently discovered iron-pnictides, iron-chalcogenides, and oxybismuthides. We discover that all these families often possess two types of SC domes, with lower and higher SC transition temperatures Tc, both unconventional but with distinct SC and normal states properties. The lower Tc dome arises with or without a quantum critical point (QCP), and not always associated with a non-Fermi liquid (NFL) background. On the contrary, the higher-Tc dome clearly stems from a NFL or strange metal phase, without an apparent intervening phase transition or a QCP. The two domes appear either fully separated in the phase diagram, or merged into one, or arise independently owing to their respective normal state characteristics. Our findings suggest that a QCP-related mechanism is an unlikely scenario for the NFL phase in these materials, and thereby narrows the possibility towards short-range fluctuations of various degrees of freedom in the momentum and frequency space. We also find that NFL physics may be a generic route to higher-Tc superconductivity.

Dome-Type Carcinoma of the Ascending Colon: A Case Report

Background: Dome-type carcinoma (DC) is a rare clinical entity first described by De Petris et al in 1999 followed by Jass et al in 2000. The tumor is described as a focus of adenocarcinoma contained within dense lymphoid stroma associated with dome type epithelium. Herein we report the endoscopic and pathologic findings in an additional case of DC in order to add to the limited number of documented cases. Case Presentation: An asymptomatic 78 year old male with a prior personal history of four tubular adenomas was found to have three broad-based polyps on routine surveillance colonoscopy. Pathology showed prominent lymphoid aggregates with nests of invasive adenocarcinoma that were well to moderately differentiated and contained no goblet cells. The findings were confined to the superficial submucosa. The final pathologic features were consistent with the typical appearance of dome-type carcinoma. The patient subsequently underwent an uncomplicated right hemicolectomy with an uneventful post-operative recovery. Conclusion: DC is a distinct variant of colorectal carcinoma with dense lymphoid component but devoid of microsatellite instability or EBV infection. The tumor is felt to arise from M cells associated with the follicle-associated epithelium of gut-associated lymphoid tissue within the colon. This assumption comes from the lack of goblet cells and the association with lymphoid tissue. Nearly all cases are low grade with excellent prognosis without recurrence. To our knowledge our reported case appears to be the only case found in a patient without abdominal complaints or a family history of colorectal carcinoma, as most patients have one or both findings. Through this case report we hope to bring further attention to this distinct clinical entity while adding another case to the current body of literature.Figure 1Figure 2Figure 3

Pretension simulation and experiment of a negative Gaussian curvature cable dome

This paper proposes a new pretension simulation algorithm and examines the pretension feasibility for a new type of cable dome: a negative Gaussian curvature cable dome. First, the paper gives a pretension simulation algorithm based on the fuzzy relationship between the prestress and internal force. Second, a negative Gaussian curvature cable dome is proposed and the corresponding experimental model is designed and pretensioned according to the simulation results from the proposed simulation algorithm. The results indicate that the pretension simulation algorithm is efficient and accurate for simulating the pretension process and guiding the practical pretension. And the results also confirm that the negative Gaussian curvature cable dome can be pretensioned successfully, thus it can be constructed as a new type of cable dome.

Design and Performance Analysis of Floating Dome Type Portable Biogas Plant for Domestic Use in Pakistan-manufacturing Cost Optimization

Design and Performance Analysis of Floating Dome Type Portable Biogas Plant for Domestic Use in Pakistan-manufacturing Cost Optimization