Base Of Column Research Articles

Sacral Fractures Treatment: Systematic Review and Meta-Analysis

Abstract Background The sacrum is a keystone structure that is important to the structural integrity of the base of the spinal column and posterior pelvic ring. Therefore, depending on the fracture pattern, fracture of the sacrum may have implications on posterior pelvic or spinopelvic stability. Sacral fracture classifications are based on fracture location, pattern of instability, and risk of neurologic deficits. Objective To review the literature about sacral fractures and to provide cumulative data about the outcome of different surgical modalities in management of sacral fractures. Patients and Methods This review was done using standard methodology outlined in the Cochrane Handbook and reported the findings in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines. Results We found 176 record; of them 82 unique records identified (duplicate removed) by the database searches; 94 were excluded based on title and Abstractreview; 82 article are searched for eligibility by full text review; 33 article cannot be accessed; 8 studies were reviews and case reports; 17 were not describing functional outcome; the desired procedure not used in 10 studies leaving 14 studies that met all inclusion criteria. Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2022. Conclusion Spinopelvic surgical stabilization represents the “gold standard” for sacral fractures treatment, this technique guarantees stability, neutralizes flexion deformation, allowing early mobilization of the patient, ensuring a reduction of comorbidities and a better recovery of neurologic lesions.

Frontier of the Paleo-Tethys Ocean in the western Mediterranean: Isotopic (Sm-Nd) constraints on sources of Devonian units from Menorca Island

The c. 1000-m-thick pre-orogenic Devonian mainly metapelitic sequence of North Menorca Island shows a fairly complete stratigraphic succession. The rocks of this sequence indicate gradually increasing deeper marine conditions of sedimentation towards its uppermost levels. Furthermore, the obtained sedimentary characteristics resemble those related to a deep and narrow basin-associated deposit. Thin sills of Ti-augite-bearing alkaline gabbros occur within the Devonian sequence. The intensity of Variscan deformation increases downwards through the structure. According to the characteristics of the Devonian sequence and its location within the Variscan Orogen, a correlation with similar units located in the southern sectors of the Central Iberian Zone (Iberian Massif) is suggested. The Devonian metapelitic rocks have geochemical characteristics suggesting that they represent moderately recycled mature siliciclastic sediments, generated from erosion of distant source areas belonging to an upper continental crust. The relatively narrow range of variation observed in initial 143Nd/144Nd ratios supports a similar source for the Menorcan slates (0.51165–0.51182). However, a marked trend is observed in these isotope ratios, from lower values at the base of the stratigraphic column (minimum value of 0.511941) to higher values at the top (maximum value of 0.512131). The 147Sm/144Nd ratios vary between 0.1074 and 0.1238, within the range defined for siliciclastic rocks with felsic crustal provenance. The Nd model ages define a narrow range between 1496 Ma and 1754 Ma (Late Paleoproterozoic–Early Mesoproterozoic), and they are consistently younger up-section. These data rule out a provenance from the erosion of the West Africa Craton, as they are more compatible with a provenance from regions located in the Trans-Saharan Belt or Sahara Metacraton. The characteristics of the Menorcan Devonian sequence are compatible with its deposition in a narrow and deep peri-Gondwanan transtensional basin, generated to the south of an advancing Variscan orogenic wedge. Systematic variations in the Nd isotopic composition indicate the progressive and continuous denudation of increasingly more easterly North African sectors in a collisional context between Laurussia and Gondwana with a marked dextral component. These data must be interpreted in the sense that there was not a large oceanic domain during Devonian times to the south of Iberia, able to block the arrival of detrital material from North Africa. A large tract of the Paleo-Tethys Ocean would therefore not have existed during the Devonian south of Iberia. This ocean must therefore have had limited extent in this period towards the westernmost sectors. The Devonian peri-Gondwanan shelf was apparently continuous around Iberia. This platform was progressively affected by Variscan deformation advancing from north to south and incorporated into the Variscan orogenic wedge with the same vergence.

Dispersion evaluation of hydrogen sulfide inclusion in a cryogenic distillation pilot plant

AbstractA risk analysis simulation was completed for a cryogenic distillation (Cryo‐D) pilot operation processing a natural gas feed stream containing H2S. This study placed significant H2S concentration inside the Cryo‐D and evaluated its dispersion after a simulated leak within the pilot plant. Sensitivity analysis using an in‐house process simulation identified the operating conditions that caused the highest surroundings H2S concentration. A computational fluid dynamic (CFD) dispersion simulation assessed H2S leakage at the bottom column section and its effects on operators. A case with 60 bar column pressure, −30°C inlet temperature and 10% H2S input gas had the highest mass flow rate of 4.74 kg/h H2S through a leak. Leaked H2S covers 50% of the building within 60 s. Within 120 s, H2S accumulates toward the column bottom. At 120 s, most operators are exposed to above 1000 ppm H2S, which may cause fatalities instantly. Recommendations include enhancing the ventilation of the building by installing ventilation near the base of the cryogenic column in order to lessen the exposure concentration. In conclusion, H2S leakage from an indoor Cryo‐D pilot plant can cause catastrophic consequences due to its rapid dispersion and accumulation throughout the building.

Closing the Water Balance with a Precision Small-Scale Field Lysimeter.

We developed a set of two precision, small-scale, water balance lysimeters to provide accurate measurements of bare soil evaporation. Each lysimeter comprises a soil tank, a balance assembly with load cell, a wicking drainage system, and a stilling well to measure drained water. Fiberglass wicks installed at the bottom of the soil tanks provide -60 cm of tension to the base of the soil column, and soil water drainage is quantified to close the water balance within the lysimeter. The calibrated lysimeters return mass changes with uncertainties ranging from 3 to 8 g, corresponding to uncertainties of 0.02-0.05 mm of water. Installed at a semi-arid site in northern Nevada, the two lysimeters are filled with uniform construction sand and silt loam. Over a six-month pilot observation period, bare soil evaporation rates of 0.19 and 0.40 mm/day were measured for the construction sand and silt loam, respectively, which is consistent with meteorological data and models of potential evapotranspiration at the site. The design of the lysimeter can be adapted to specific research goals or site restrictions, and these instruments can contribute significantly to our ability to close the soil water balance.

Identifying ZDR Columns in Radar Data with the Hotspot Technique

Abstract A novel differential reflectivity (ZDR) column detection method, the hotspot technique, has been developed. Utilizing constant altitude plan projection indicators (CAPPI) of ZDR, reflectivity, and a proxy for circular depolarization ratio at the height of the −10°C isotherm, the method identifies the location of the base of the ZDR column rather than the entire ZDR column depth. The new method is compared to two other existing ZDR column detection methods and shown to be an improvement in regions where there is a ZDR bias. Significance Statement Thunderstorm updrafts are the area of a storm where precipitation grows, electrification is initiated, and tornadoes may form. Therefore, accurate detection and quantification of updraft properties using weather radar data is of great importance for assessing a storm’s damage potential in real time. Current methods to automatically detect updraft areas, however, are error-prone due to common deficiencies in radar measurements. We present a novel algorithmic approach to identify storm updrafts that eliminates some of the known shortcomings of existing methods. In the future, our method could be used to develop new hail detection algorithms, or to improve short-term weather forecasting models.

Liparis bomiensis (Orchidaceae, Epidendroideae, Malaxideae), a new species from Xizang, China

Liparis bomiensis, a new species of Orchidaceae from Bomi County, Linzhi, Xizang, China, is described and illustrated on morphological characters and molecular systematics. It is morphologically similar to L. rostrata with 2 thick projections at base of column, but differs from it by having purple and rhombic lip about 15 mm long, sepals and petals more than 15 mm long. Molecular phylogenetic results based on nuclear ribosomal ITS and plastid matK sequences showed that L. bomiensis is sister to L. glossula, but differs from it by having 2 thick nipple-like projections at base of column, two leaves, bracts triangular, column strongly curved. A detailed morphological description and photographic plates are provided for this new species.

<i>Epidendrum edquenii</i> (Laeliinae), a new species from a montane wet forest of the Private Conservation Area La Pampa Del Burro, Amazonas, Peru

A new species Epidendrum edquenii, is described and illustrated from the Private Conservation Area La Pampa del Burro, department of Amazonas, northeastern Peru. It belongs to the informal Takulumena group, characterized by Vanda-like monopodial stems with basal or lateral, successive inflorescences. The new species is distinguished by its non-pubescent, red flowers with green dorsal surface, margins, and apices of the sepals and petals, yellow-green base of column and disc of lip, acuminate sepals 9.5–10.7 mm long, narrowly ovate petals with the margin densely and shortly ciliate, and widely triangular lip, 6.0 × 9.5 mm, with the margin scarcely papillose. A list and an identification key for the previously known species of the Takulumena group are provided. Furthermore, the new name Epidendrum vulcanitungurahuae is proposed to replace the illegitimate combination Epidendrum tungurahuae, predated by E. tunguraguae.

Toxicity of allyl isothiocyanate applied in systems with or without recirculation for controlling Sitophilus zeamais, Rhyzopertha dominica, and Tribolium castaneum in corn grains.

The application of allyl isothiocyanate (AITC) has been proposed as an alternative to control stored-grain insects. However, AITC is a compound with a low diffusion coefficient, making its distribution throughout the grain mass difficult. Therefore, the objective of the present study was to evaluate the effectiveness of AITC applied in systems with or without recirculation for controlling Sitophilus zeamais (Mots. 1855) (Coleoptera: Curculionidae), Rhyzopertha dominica (Fabr.) (Coleoptera: Bostrichidae), and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) infesting a corn grain mass. The assays used a polyvinyl chloride (PVC) prototype, dimensioned 1.60 m in length, 0.30 m in diameter, and a static capacity of 60 kg of grains. AITC toxicity to insects was evaluated at the base, 0.5 m from the base, and top of the grain column (1.0 m). Different concentrations of AITC were tested for an exposure period of 48 h. In the system without AITC recirculation, insect mortality was verified only at the base of the grain column. However, insect mortality was considered uniform at the different positions of the column when the AITC recirculation system was adopted. In this system, there was also a marked reduction in the instantaneous population growth rate of S. zeamais, T. castaneum, and R. dominica, and a decrease in the dry matter loss of the grains, when the AITC concentrations were increased. AITC recirculation proved to be a viable strategy for protecting grains against the species S. zeamais, R. dominica, and T. castaneum. AITC fumigation ultimately did not cause changes in grain quality. © 2023 Society of Chemical Industry.

Finite Element Analysis of steel frames subjected to post-earthquake fire

Fire and post-earthquake fires pose a major hazard to our built environment. Industrial structures are generally steel structures and are many a times single storey. Risk of fire in an industrial building after an earthquake must be taken into consideration. Cascading combination of multiple hazards is essential to evaluate the real performance of a structure. The paper focused on the response of an unprotected steel frame subjected to post earthquake fire. Initially, the frame was analyzed for Earthquakes and Fire hazards independently. Time History analysis of the steel frame was carried out with the Base of Column subjected to Earthquake Time Histories. Frame damaged due to earthquakes was further subjected to Fire Hazard. Analysis for Gravity load was included in every type of Load case. Finite element tools have the ability to consider sequential loadings of Earthquake and then Fire. Fire analysis was performed considering the strength and stiffness reduction of carbon steel as per the IS800:2007. Bi-Linear stress–strain properties of steel were used considering the effect of temperature over them. The Beam-Column connections were considered rigid and Tie constraints were used to tie the surfaces of Beam to Column. The Joint Panel Zone was observed to suffer damage during the Earthquake Hazard, where the top of column was subjected to stress concentrations. Damage to the frame in a fire hazard was found to be very large compared to the damage due to earthquakes. The impact of these earthquakes on the Fire Ratings were observed considering the Post-Earthquake Fire Hazard.

Port Management Model in the Industrial Revolution 4.0 Era

Sedimentation is a natural and physical phenomenon that affects port management. If it is further elaborated, the main aspects of port management include planning, design, construction, and maintenance activities. Sedimentation can cause a decrease of depth or silting in navigation channels and port pools which to some extent, are dangerous for the inbound vessels that are calling at the port. The silting process is influenced by how much material and what type of material that settles at the base of the water column. To understand the effect of sedimentation on port management, a comparative study was conducted between the terms of port management which are stated in the regulations that apply in Indonesia and the implementation that has been carried out. realized at patimban port. The data that is compared takes the form of planning data and existing conditions in 2020 to then be reviewed with current regulations to assess its compliance with the said regulation. In order to devise technical recommendations in spatial and temporal aspects, the port authorities must have a thorough understanding of the effect of sedimentation on port management. In its implementation, spatial aspects are related to the maintenance of navigation channels and anchoring locations, while temporal aspects are related to the frequency of monitoring of the sediment deposition and sediment removal to keep the navigation channels safe for calling vessels. The monitoring process must be done in a routine and timely manner, by integrating temporal change data with Industrial Revolution 4.0-based technologies to increase the rate of data renwals, so that the manager of the port can respond to any changes that occur in the port accordingly and effectively in a short period of time.

Variable Morphology of Sacrum in General Population

Background: One of the large trilateral bones present at the base of the vertebral column is named as sacrum. The body weight transfers from trunk to pelvis and lower extremities. Different studies considering sacral morphological variations are conducted in the western world. The scope and knowledge of these studies in the eastern world is limited. Different sacral anatomies are reported by the scientists. Objective: The purpose of the study was to investigate and measure thoroughly the variable morphologies of sacrum. Study design: It is an investigational and cross-sectional study facilitated by statistical approach. Material and Methods: The study was conducted on 223 skeleton samples. These samples were preserved in the anatomy department of Mufti Mehmood Teaching Hospital Dera Ismail Khan and Bacha Khan Medical Complex Swabi during the period from October 2021 to June 2022. The human research ethical committee of the hospital approved the study. The vernier caliper was used to measure the correlation parameters of variability. The morphological features were calculated. The study also calculated the sacral variation incidence. The sacra with any kind of bony defects were excluded from the study. Results: The anatomical differences reported in the 223 samples were observed to be 59%. Out of the 223 patients the 81 were females and 142 were males. The five variations were reported in the sacral regions, while two samples have the rare sacral variations. The mean age of the included sample was observed to be 44 years. The age of the people whose sacral samples were included in the study was between 21-72 years. The percentage incidence of accessory auricular faces was observed to be 12.5%. The sacral skewness was observed in 24% cases. The 17% showed the transitional vertebra, while sacral spina bifida occulta was seen in 28% samples. Conclusion: This large scale anatomical study provides information about the apparent changes in the morphology of different sacral variables. This study provides comprehensive data about the different sacral variations. The detailed information about the human sacrum is provided. The apparent identification methods by western medical officers are also considered in this work which may help our medical staff to identify the sacral variations. Keywords: Sacrum variations, Sacrum morphology, Accessory auricular faces, Transitional vertebra and Sacral spina bifida occulta

A novel double disc method to determine soil hydraulic properties from drainage experiments with tension gradients

Determination of the saturated hydraulic conductivity, Ks, and the water retention curve, θ(h), is of paramount importance to characterize the hydraulic behavior of the vadose zone. Given the van Genuchten hydraulic model, defined by the residual, θr, and saturated, θs, volumetric water content and the α and n parameters, this work presents a new laboratory procedure to estimate Ks, θs, n and α for a drainage process, αdr, from the inverse analysis of successive drainage steady-states curves generated by a tension-gradient between the surface and the base of a soil column. To this end, a double disc system, one connected a bubbling tower and placed at the soil surface and the second one placed under the soil core, was employed. The second disc was connected to an air-vacuum system. The experiment presented two parts: a first 1D downward infiltration at saturation on a dry soil column, followed by successive drainage steps. During the drainage process, the tension of the upper and lower discs varied between 0 and −5 cm, and from −5 to −100 cm, respectively. The soil sorptivity, S, and θs were calculated from the 1D transient infiltration measure, Ks was calculated by Darcy’s law, αdr and n were optimized from the inverse analysis of the steady-state curves under tension-gradient and α for a wetting process, αw, was calculated from previously obtained S, θs, Ks and n. Once Ks estimated, αdr and n were optimized by minimizing the Q=hb-hn objective function, where hb and hn are the experimental and calculated tensions at the base of the soil core. Given a αdr value, the optimimum n was computed as the value that provides a minimum Q. By repeating this process for a sequence of αdr, different Q-isolines were obtained, one for each hb value, which crossing-point corresponded to the actual αdr and n values. The method was tested on 2.5 cm high columns of four different synthetic soils. Next, it was applied on an experimental sand column of 5 cm height and on 2.5 cm high columns filled with sieved loam, clay loam and clay soil. The estimated αdr and n were compared with corresponding values measured in the same soils with the pressure plate technique and αw was contrasted with the corresponding value calculated with an empirical hysteresis model. The method, which was fast (from 1 to 2 h) and easy to implement for small-scale experiments, was successfully applied to soil samples 2.5 cm high and allowed to explore a range of soil tensions from 0 to −100 cm. Overall, accurate estimates of θs, Ks, αdr and n were obtained in both synthetic and experimental soils. A significant relationship was also obtained between αw estimated from S and the corresponding value calculated from the hysteresis model.

Digital geologic map, petrography and U-Pb geochronology of the Río Santiago Shear Zone, southernmost Sierra Madre Occidental, western Mexico

The boundary between the Sierra Madre Occidental (SMO) and the Trans-Mexican Volcanic Belt (TMVB) is well exposed along the Santiago River, on the border of the states of Nayarit and Jalisco. This region includes a polydeformed belt produced by the relative motion between the Jalisco Block and the SMO, here defined as the “Rio Santiago Shear Zone” (RSSZ). In this work, we present detailed geological cartography, petrographic descriptions, and new zircon U-Pb ages that allow us to establish the stratigraphy of the region surrounding the RSSZ, providing temporal constraints to its tectonic evolution. In the mapped area, the base of the SMO stratigraphic column consists of a succession of massive andesitic lava flows intruded by felsic dikes and a felsic subvolcanic body of 27.5 and 27.2 Ma, and it is covered by a series of ignimbrites of 26.8 and 25.3 Ma. A red beds succession separates a second package of ignimbrites of ∼20-19 Ma, in turn capped by rhyolitic lava domes of 19.7 and 18.6 Ma and a rhyodacitic lava flows of 15.6 Ma, this Miocene succession is also intruded by a felsic body of 18.3 Ma west of the La Yesca dam. The SMO succession is covered by rocks belonging to the bimodal volcanism of the TMVB, emplaced between the end of the Miocene and the Pleistocene. The RSSZ developed through several deformation phases that occurred since the end of the Oligocene. The Oligocene succession of the SMO is affected by NE-SW and WNW-ESE trending lateral faults, NW-SE open folds and WNW-ESE and E-W trending reverse oblique faults. Some of the reverse oblique faults were later reactivated as normal faults. WNW-ESE trending normal faults associated with the Tepic-Zacoalco Rift affected the area south of the Santiago River during the Pliocene and Pleistocene. Normal faulting produced an accumulated vertical offset up to 700 m between the northern and southern regions of the Santiago River.

Heat flow and 2D multichannel seismic reflection survey of the Devil's Hole geothermal reservoir in the Wagner basin, northern Gulf of California

The Wagner basin, located in the northernmost Gulf of California, hosts a large reservoir with geothermal potential documented in recent heat flow surveys. Although there is evidence of heat generation above the average value for an oceanic crust in the Wagner basin, it is unclear what the heat source is. To better understand the thermal structure in the northern Gulf of California, we acquired four 2D multichannel seismic reflection profiles and two systematic heat flow profiles across the Wagner basin. The survey targeted a geothermal anomaly, which we denominated “Devil's Hole” in a clear reference to pockmarks on the seafloor, and very high heat flow values. The heat flow profiles are ∼12 and ∼9 km long, are sub perpendicular to each other, have a nominal measurement spacing of ∼1 km, and were located along the transects of two of the four seismic reflection profiles. The two remaining seismic profiles are ∼34 and ∼40 km long, respectively, and are oriented SWW-NEE. To obtain seismic images, we used a conventional seismic processing workflow. After heat flow data correction, the minimum, maximum, and standard deviation of heat flow values for the Wagner basin are 295±42 and 10,894±114 mW/m2. We interpret the relatively high heat flow and large variability in the central part of the acquired profiles is caused by upward fluid flow at the Wagner fault zone. In contrast, the lower heat flow in the western flank of the basin suggest conductive heat transfer given the absence of faults. Based on these observations, we develop a geological model in which venting is not the product of a nascent spreading center as other authors have suggested. Instead, hydrothermal activity appears to result from isolated thermal plumes, rising from the base of the sedimentary column, captured by permeable fracture systems.

Design of Pile Foundation for Distillation Column

Abstract Equipment foundation is one of the most critical facility in every petrochemical, fertilizer, oil and gas plants. This equipment comprises distillation columns, vertical vessels, horizontal vessels, high pressure exchangers, reactors etc. Out of this equipment, distillation column is one of the most critical equipment due to its large diameter and height hence resulting into heavy dead load and heavy transverse loads at the base of column. Hence proper foundation system should be designed to cater all these loading without affecting the strength and serviceability of the foundation system. In most of the cases due to poor bearing capacity of soil one need to go for pile foundation. This paper summarizes the Indian code and process industry practices, design loads and load combinations to be adopted for design of pile foundation. One sample example is solved to evaluate the no of piles for column foundation by assuming suitable loading and vessel data.

Triple oxygen isotope systematics of diagenetic recrystallization of diatom opal-A to opal-CT to microquartz in deep sea sediments

The oxygen-18 isotopic composition (δ18O) of silica preserved in oceanic sediments is an important archive of Earth’s temperature and/or seawater δ18O from the Archean to present. Recent advances in high-precision measurements of both δ18O and δ17O values have been used to provide additional constraints on what the oxygen isotopic composition of chert reflects about past conditions. Here, we examine the effects on the triple oxygen isotopic composition of chert that occurs during transformation and recrystallization of biogenic opal-A to opal-CT to microquartz in deep sea sediments. We studied late Miocene to present samples from the Sea of Japan at ODP Site 795 and measured biogenic diatom opal-A, opal-CT, microquartz chert, and ‘altered’ opal-A samples—previously measured for δ18O values only—for both δ18O and δ17O values. We find that δ18O decreases and Δ′17O increases (where Δ′17O = δ17O – 0.528 × δ18O) with depth, coincident with the conversions from diatom opal-A to opal-CT to microquartz. Silica samples deviate from the trend expected for triple oxygen isotopic equilibrium with modern seawater. To explain these data, we developed a model that shows that local temperature gradients and pore fluid δ18O profiles in combination lower the measured opal-CT and microquartz δ18O values and raise the Δ′17O values relative to the initial opal-A, but deviate from triple oxygen isotopic equilibrium with seawater. We find that a steeper local temperature gradient and a larger influence of hydrothermal alteration of basalt at the base of the sediment column (which lowers pore fluid δ18O values) in the past explain both the measured δ18O and Δ′17O values of the opal-CT and microquartz.These data and our modeling show that the transformation of opal-A to microquartz in marine sediments at elevated temperatures and in the presence of lowered pore water δ18O values leads to an array that falls below the theoretical triple oxygen isotope line of equilibrium for SiO2 with modern seawater. Further, our model indicates that opal-CT and microquartz do form in triple oxygen isotopic equilibrium with pore fluids that are offset in their triple oxygen isotopic composition compared to seawater due to fluid-rock alteration of igneous rocks at the base of the sediment column. The diagenetic processes taking place in the Japan Sea do not explain a large portion of the existing Archean to present triple oxygen isotope chert data, which likely require either changes in the oxygen isotopic composition of the source water (i.e., ocean water) and/or alteration by meteoric fluids. Further, our data demonstrate that the triple oxygen isotopic composition of preserved chert need not represent surface conditions, but instead may reflect processes that occur in subsurface sediments at elevated temperatures and with modified pore fluid oxygen isotopic compositions.

АНТИЧНЫЕ ПОСЕЛЕНИЯ ГОРОДСКОГО ТИПА НИЗМЕННОГО КАРАБАХА

The archaeological research indicated a large number and significant density of settlements of different times on the territory of Azerbaijan, which is mainly due to the fact that there were all the necessary conditions for the emergence of settlements. The decisive condition for their emergence has always been the presence of certain material prerequisites for life, as well as the possibility of defending a given area. The analysis of archaeological materials draws a picture of life in the cities of Albania in the period of antiquity. These cities were administrative and trade and craft centers with developed money circulation. In the cities of Albania, such types of handicrafts as pottery, metallurgy and metalworking, jewelry, glass making, as well as weaving and leatherworking were developed. In their development, a significant role played the trade routes of that time passing through the territory of Albania, one of which was the waterway along the Kura River. Keywords: Albania, Karabakh, cities, base of column, defensive walls

Evaluation of the Filum Terminale in Hereditary Equine Regional Dermal Asthenia.

The objectives of this study were to describe the anatomy, histology, and ultrastructure of the equine filum terminale (FT) and to describe the FT in hereditary equine regional dermal asthenia (HERDA), a model of human Ehlers-Danlos syndromes (EDS). Those humans suffer from tethered cord syndrome (TCS) caused by an abnormally structured FT wherein its attachment at the base of the vertebral column leads to long-term stretch-induced injury to the spinal cord. The pathophysiology of TCS in EDS is poorly understood, and there is a need for an animal model of the condition. Histopathologic and ultrastructural examinations were performed on FT from HERDA (n = 4) and control horses (n = 5) and were compared to FT from human TCS patients with and without EDS. Adipose, fibrous tissue, and neuronal elements were assessed. CD3 and CD20 immunohistochemistry was performed to clarify cell types (HERDA n = 2; control n = 5). Collagen fibrils were assessed in cross-section for fibril diameter and shape, and in longitudinal section for fibril disorganization, swelling, and fragmentation. The equine and human FT were similar, with both containing fibrous tissue, ependyma, neuropil, and nerve twigs. Hypervascularity was observed in both HERDA horses and human EDS-TCS patients and was not observed in equine or human controls. Moderate to severe abnormalities in collagen fibril orientation and architecture were observed in all HERDA horses and were similar to those observed in human EDS-TCS patients.

The effect of input ground motion location on design spectrum in a seismic ground response analysis performed for an alluvial site

Site response analyses are performed to estimate the change in the characteristics of the input rock motion occurred during the vertical propagation of seismic waves and to obtain the local variation in intensity and spectral characteristics of surface ground motion. The rock outcrop motions which are selected by considering the source mechanism, fault distance and earthquake characteristics that are compatible with the standard design ground motion level. It is generally agreed that time domain simulated or spectral matched ground motions may be applied as input ground motions at seismic bedrock in the dynamic response analysis of soil layers under earthquake excitation and thus shear stresses and deformations, acceleration-time histories and site-specific design spectrum can be obtained for surface layers. In “Turkish Building Earthquake Code (TBEC), 2018” it is being stated that the input ground motion can be exerted at the base of a soil layer lying at a shallower depth in comparison with seismic bedrock depth by using the method of spectral matching the accelerograms to the target spectrum of corresponding soil layer where the input motion is applied. In this study, by evaluating and combining the findings of the geotechnical borings and microtremor array measurements, the shear wave velocity profiles extending to seismic bedrock (VS≥760 m/s) were obtained for the investigation sites. The results of the site response analyses that were conducted by using the two different methods proposed in TBEC (2018) were interpreted. At the first method, in deeper 1D dynamic analyses, the input ground motions were applied at seismic bedrock defined as site class ZB where the shear wave velocity (VS30) is higher than 760 m/s2. Whilst at the second method, the inputs were applied at the base of the shallower 1D soil column having site class either ZC or ZD where VS30 is in the range of 360 m/s2 < VS30 < 760 m/s2 and 180 m/s2 < VS30 < 360 m/s2 respectively. As a result, the acceleration spectra obtained on the surface of deep and shallow models were compared for 31 strong ground motion records, selected in accordance with the design spectra corresponding to seismic code depending on the location of the investigation area and local site classes.

Validation of the calculation of a wooden column with a support unit on glued steel plates

The article proposes a structural solution for the base of a wooden frame column on flat links glued in the support part of the column – steel plates welded to the base plate. The results of numerical studies of the column, taking into account the parameters of the adhesive connection of the plates with wood and the anisotropy of wood, are presented. The column model takes into account the geometric and physico-mechanical characteristics of wood, steel plate bonds and adhesive compound. The main results of numerical studies are verified with the results of the analytical calculation of the column performed by the method of initial parameters. A physical model with the proposed structural solution of the column base was made and tested. The numerical and analytical calculations of the column were validated, and the main conclusions of the experimental and theoretical study were presented.