Zone 1B Research Articles

Efficient repair of the flexor digitorum profundus tendon at the insertion site using the loop suture technique: a case series

Purpose: This study presents the outcomes of a modified loop-locking suture technique for repairing complete flexor digitorum profundus (FDP) tendon divisions at the terminal level. Traditional methods, such as pullout sutures or tendon fixation, are commonly used; however, this paper explores the reliability of the loop-locking suture technique.Methods: From June 2011 to January 2024, the modified loop-locking suture technique was performed in 21 cases of FDP tendon division in which the distal stump was less than 1 cm in length. Core and epitendinous sutures were made using polydioxanone 4-0 and poliglecaprone 25 4-0. The study focused on 13 patients aged 24 to 68 years, with an average tendon stump length of 0.61 cm. Ten cases necessitated microsurgical repair involving both arterial and nerve repair. A dorsal protective splint was used for an average of 5 weeks. The outcomes measured included active and passive range of motion, grip strength, and key and pulp pinch.Results: The mean follow-up period was 12 months. No re-ruptures occurred, although two cases required tenolysis. The average active range of motion at the distal interphalangeal joint was 61.5°. Grip strength and pulp pinch averaged 95.3% and 86.8%, respectively, compared to the contralateral side. Flexion contracture was observed in three cases, with no quadriga effect.Conclusion: The modified loop-locking suture technique provides sufficient functional recovery for FDP tendon divisions in Zone 1a and distal Zone 1b, even with a short tendon stump.

Data Center Energy Evaluation Tool Development and Analysis of Power Usage Effectiveness with Different Economizer Types in Various Climate Zones

Data centers are energy-intensive facilities, with over 95% of their total cooling load attributed to the heat generated by information technology equipment (ITE). Various energy-saving techniques have been employed to enhance data center efficiency and to reduce power usage effectiveness (PUE). Among these, economizers using outdoor air for cooling are the most effective for addressing year-round cooling demands. Despite the simplicity of the load composition, analyzing data center cooling systems involves dynamic considerations, such as weather conditions, system conditions, and economizer control. A PUE interpretation tool was specifically developed for use in data centers, aimed at addressing the simplicity of data center loads and the complexity of system analysis. The tool was verified through a comparison with results from DesignBuilder implementing the EnergyPlus algorithm. Using the developed tool, a comparative analysis of economizer strategies based on the PUE distribution was conducted, with the aim of reducing the PUE of data centers across various climatic zones. The inclusion of evaporative cooling (EC) further improved cooling efficiency, leading to reductions in PUE by approximately 0.02 to 0.05 in dry zones. Additionally, wet zones exhibited PUE reductions, ranging from approximately 0.03 to 0.07, with the implementation of indirect air-side economizer (IASE). Sensitivity and uncertainty analysis were further conducted. The computer room air handler (CRAH) supply temperature and CRAH temperature difference were the most influential factors affecting the annual PUE. For the direct air-side economizer (DASE) and DASE + EC systems, higher PUE uncertainty was observed in zones 1B, 3B, 4B, and 5B, showing ranges of 1.17–1.39 and 1.15–1.17, respectively. In the case of the IASE and IASE + EC systems, higher PUE uncertainty was noted in zones 0A, 0B, 1A, 1B, and 2A, with ranges of 1.22–1.43 and 1.17–1.43, respectively. The distinctive innovation of the tool developed in this study is characterized by its integration of specific features unique to data centers. It streamlines the computation of cooling loads, thus minimizing the burden of input, and delivers energy consumption data for data center cooling systems with a level of precision comparable to that of commercial dynamic energy analysis tools. It provides data center engineers with a valuable resource to identify optimal alternatives and system design conditions for data centers. This empowers them to make informed decisions based on energy efficiency enhancements, thereby strengthening their ability to improve energy efficiency.

Controls on mechanical properties of a carbonate mudstone: Insights from non-destructive techniques and geochemical data

This study quantifies geomechanical properties of carbonate mudrocks in the Arabian intra-shelf basin, focusing on different sedimentologic zones (proximal to distal). Core-based mechanical properties were obtained through unconfined conditions. Micro Rebound Testing (MRT) was conducted on 700′ ft of core at 0.5 ft intervals to capture high-resolution rock hardness (HLD), unconfined compressive strength (UCS), and static Young's Modulus (E). Additional tests validated log-based parameters, including impulse hammer, acoustic velocity testing for (E), P-wave and S-wave velocities (Vp and Vs), scratch testing, and XRF/XRD analyses for mineralogical and elemental variability impact on mechanical properties.Multivariate statistical analysis correlates mechanical properties with elemental data, showing direct proportionality to calcium percentage, (E), Vp, and Vs, while inversely correlated to aluminum, iron, sulfur, and total organic carbon (TOC), especially in distal zones. Porosity, as measured by neutron porosity log, is a significant control on mechanical properties, with higher porosity resulting in lower mechanical properties at any given calcium percentage. Variations in geomechanical properties within each zone are principally controlled by depositional environments, sediment supply, diagenesis, and a pycnocline dividing the water column into anoxic, dysoxic (or suboxic), and oxic conditions.Zone 1A and 4 exhibit high brittleness characterized by high Ca-calcite, HLD, (E), Vp, Vs., low terrigenous elements/minerals, and porosity. Zone 1B and 2A are moderately brittle, showing a slight decrease in brittleness and a slight increase in terrigenous elements/minerals, porosity, and organic matter, particularly in the distal zone (Zone 1B). Zone 2B, 3A, and 3B represent moderate to highly ductile zones with low levels of Ca-calcite, HLD, (E), Vp, Vs, and an increase in terrigenous elements/minerals, porosity, and TOC, especially in the distal zone (Zone 2B and 3B). This study highlights the value of high-resolution mechanical data from cores with applications for improved stress estimation and hydraulic fracture stimulation in unconventional reservoirs.

Costs, Returns, Resource Use Efficiency of American Cotton Production in Irrigated North Western Plain Zone of Rajasthan, India

The study was carried out at Irrigated North Western Plain Zone 1b of Rajasthan in agricultural year 2012-13. This zone covers about 80 percent of the total area of cotton in the state. The study focused on the cost and return, efficiency of resource use and problems faced by the farmers in American cotton production under different farm sizes. Two villages namely 4C and Mirjawala were selected from Sriganganagar tehsil of the zone. Thirty farmers were selected at random in proportion to the total number of farmers in each size group from the list of from American cotton farmers group. The total variable cost of per hectare American cotton was Rs 28985. The yield per ha was 18.70 quintals. The return over variable cost per hectare American cotton was Rs 61436. The Cobb Douglas production function, revealed that the in American cotton farmers were underutilized fertilizer. Non-availability of labour during peak season was reported as highly acute constraint for cotton farmers. The damage caused by insect pests was reported as main problem for American cotton sample farmers.

Hydrocarbon evaluation and distribution in Well-X and Well-Y in the Niger Delta Basin: Findings and validation through porosity comparison

The aim of this study is to integrate well logs and core data to identify reservoir characteristics and determine the reservoir's petrophysical properties in order to improve the understanding of the reservoir and provide valuable information for reservoir management. Wells X and Y of the ‘SCOJAS’ Field in the Niger Delta Basin of Nigeria were analyzed using Gamma ray logs, Resistivity logs, Sonic, Neutron and Density Logs. The obtained results were compared with core data from the wells to verify their accuracy. Porosity values for Wells X and Y fall within the range typically observed in sedimentary rocks, with Well Y having higher values. Hydrocarbons were detected in all reservoirs except reservoir zone 1b in both Well-X (12 reservoirs) and Well-Y (7 reservoirs). In Well- X, oil was identified in 5 reservoir zones while in Well-Y, oil was present in 2 reservoir zones. The remaining zones in both wells contained gas. To validate the results further, a comparison was made with the porosity of selected fields in the Niger Delta Basin and the general porosity of the Basin. Well X has a porosity range of 2.7% to 20.8%, which is generally lower than the reported porosity range Well Y has a porosity range of 19.90% to 24.38%, which falls at the upper end of the reported porosity range. Comparing previous works and data from other fields provides important validation for the findings of the study, which is crucial in the oil and gas industry for making informed decisions about exploration and production.

Multi-objective optimization of latent energy storage in buildings by using phase change materials with different melting temperatures

Technologies based on phase change materials (PCMs) are promising solutions to reduce energy consumption in buildings and related greenhouse gas emissions. However, the performance of passive PCMs in buildings is highly dependent on the melting temperatures employed, as well as the climate where the building is located. Therefore, the present contribution describes an optimization-based method to design passive latent energy storage in buildings by using PCMs with different melting temperatures. To achieve this goal, a multi-objective genetic algorithm is coupled with the building energy models developed in EnergyPlus to find the best trade-off between annual heating and cooling loads. A small office is chosen as a case study to evaluate the energy performance of the buildings incorporating the proposed PCM approach. Three different PCM layers are added to the ceilings and the external and internal walls of the building, and their parametric models are developed in EnergyPlus to optimize the melting temperature and thickness of each PCM layer simultaneously. Moreover, a method to select climate-representative locations according to the ASHRAE 169-2020 climate classification and within the WMO Region VI (Europe) is proposed and applied, resulting in eight well-representative locations. An optimization-based design is carried out for each selected location and the performances of the optimized building designs are systematically compared to the ones of the baseline models. The optimization results achieved show that regardless of the climate zone analyzed, using several PCMs with different melting temperatures instead of a single one, is preferred. Moreover, the best performance of PCMs is attained in climate zones where both the heating and cooling loads are present. Thus, the highest saving regarding the annual total loads of 11.7% is achieved in zone 5A (Cold), while the lowest one of 2.3% is obtained in zone 1B (Very hot).

Comparative Study of Paddy Cultivation in Ghaggar River Belt and Salt Affected Micro Farming Situation in Zone 1b of Rajasthan

The present study was conducted to analyze the comparative calculation of the cost and returns and resource use efficiency of paddy crop in Ghaggar river belt and Salt affected micro farming situations in zone 1b of Rajasthan. In zone Ib Sriganganagar district Suratgarh tehsil selected for Ghaggar river belt and in Hanumangarh district Rawatsar tehsil selected for Salt affected micro farming situation. Two villages from each tehsil were selected randomly. A sample of 50 farmers was selected for the present study for each tehsil. The farmers were divided into small, medium and large farms on basis of following criterion; Small (≤2ha), Medium (>2ha ≤4ha) and Large (>4ha). A sample of 25 farmers from each village was selected according to probability proportional to farm size. Primary data were collected on pre-structured schedules for agriculture year 2017-18. In study area overall cost of cultivation per hectare of paddy ₹ 46110.02 and ₹ 37750.44 in Ghaggar river belt and Salt affected micro farming situations respectively. Gross return in Ghaggar river belt micro farming situation was ₹ 100852.50 and Salt affected micro farming situation was ₹ 79772.50 per hectare. Coefficient of multiple determinations (R2) in Ghaggar river belt micro farming situations found 0.75 per cent and Salt affected micro farming situation 0.62 per cent.

Outcomes of flexor tendon repairs in the zone 1 subzones with an immobilization protocol

We report on the outcomes of flexor tendon repair in zone 1 subzones with an immobilization protocol in four fingers in four consecutive patients (29% of the patients undergoing zone 1 tendon repairs in the same period). One finger had a zone 1A injury, two had zone 1B injuries, and one had a zone 1C injury. The mean active range of motion of the distal interphalangeal joint was 34°. Using Moiemen’s criteria, one finger (zone 1A) was rated as excellent and three as poor. Not all zone 1 injuries treated with immobilization protocols had poor outcomes in our series. The functional results of an immobilization protocol for zone 1A seemed to be superior to those for zones 1B and 1C. We speculate that differences in the local anatomy of the flexor digitorum profundus tendon and neighboring structures may influence the outcomes in the zone 1 subzones with an immobilization protocol.

Contrast CT-scan for preoperative planning of VSLN (vascularized submental lymph-node) transfer.

Vascularized submental lymph-node (VSLN) transfer is gaining popularity as a reliable donor-site in microsurgical treatment of lymphedema. However, variations in number, location, and blood supply to submental lymph-nodes as well as associate skin-paddle make a predictable flap harvest a challenging task. We analyzed this region on preoperative imaging, to improve accuracy of VSLN transfers. Contrast CT-scan analysis of VSLN-flap areas was performed in 58 patients. Number and location of visibly vascularized lymph nodes as well as submental artery perforators were identified, documented, and compared. About 409 lymph-nodes were found in 50 patients. No significant difference was found in the number of nodes between the right and left side. Significantly more lymph-nodes were found in zones 1B than zones 1A. In eight patients nodes were not identified. In the remaining 50 patients position of the visibly vascularized submental lymph-node was predictable. Significantly less lymph-nodes can be found in zone 1a then zone 1b. Location of visibly vascularized lymph nodes can be identified predictably in relation to bony landmarks. Blood supply to 1a nodes and particularly location of dominant skin perforator is unpredictable due to potential crossover. Contrast CT scan can help identify location and blood supply to submental lymph-nodes in most patients. J. Surg. Oncol. 2017;115:23-26. © 2016 Wiley Periodicals, Inc.

Characterization of Citrus Rootstocks Under Sriganganagar Conditions of Zone 1B

Investigation was carried out to evaluate and characterize the available citrus rootstocks and to find out the genetic variability and correlation in between the qualitative/quantitative traits. Fully grown, eleven Citrus types i.e. C. maderaspatana, C. jambhiri var. Mitthi, C. Pectinifera, C. Reshni T, Citrumelo (P. trifoliata x C. sinensis), Carrizo Citrange (P. trifoliate x C. paradisi), C. limonia, C. Karna, C. aurantium, C. Jambhiri var. Jatti-katti and C. limon var. Bhadri Lemon were selected for the study. These exhibited variation for different physico-chemical fruit and seed attributes. Variation in seed characters were also recorded for seed shape, number and colour of cotyledons. Variation were noted for quantitative traits like fruit length (24–210 mm) fruit weight (19–1883 g), TSS (7–10); seed length (7–16 mm), hundred seed weight (16–31 g) and seed number per fruit (2–55). In character association analysis, positive and significant correlation were recorded for fruit weight with fruit size, seed weight with seed size and seed weight with seed germination. Thus, the study revealed that significant amount of genetic variability exists among the available rootstocks. Genetic variability and inter relationship of characters may lead to effective selection of rootstock for commercial multiplication and further improvement programme of citrus plants.

English

Abdominal wall reconstruction is a difficult problem to treat especially in presence of scarred tissue and associated other complications. The abdomen is divided into different zones for the purpose of reconstruction. Lower abdomen consists of zones 1B and 3. There a various options for lower abdomen reconstruction and groin flap is one of them. Although tensor fascia lata flap has been frequently used option we found groin flap to be quiet handy for lower abdomen reconstruction. We used groin flap for closure of this defect and found it very useful, easy and dependable.

Multilocational validation of integrated management practices for Sclerotinia rot of Indian mustard (<i>Brassica juncea</i>)

Field studies were conducted from 2008 to 2011 on integrated management of Sclerotinia rot of Indian mustard (Brassica juncea L. Czerns & Coss.) involving Trichoderma mixture (T. viride + T. hamatum) formulation (2×109 cfu/g) through seed treatment (10 g/kg), soil application (2.5 kg/ha) pre-incubated in farmyard manure and foliar sprays (0.2%) at 50 and 70 days after sowing along with improved cultural practices at Indian Agricultural Research Institute, New Delhi, which reduced the disease incidence up to a minimum of 11.1% and increased the seed yield up to a maximum of 2.72 tonnes/ha as compared to control (disease incidence 26.9% and seed yield 1.77 tonnes/ha). Validation of management practices were also undertaken during 2008 to 2011 in farmer’s participatory mode under three different agro climates, Zone 1b and 3b in Rajasthan and south-west zone in Haryana. The validation studies revealed that integrated management strategies based on Trichoderma resulted in minimum Sclerotinia rot incidence (mean values of three regions 5.6%) and maximum seed yield (2.19 tonnes/ha) as compared to garlic clove extract (mean values 10.3% and seed yield 1.90 tonnes/ ha) and Farmers’ practices (mean values 19.2% and seed yield 1.66 tonnes/ha). Integrated management strategies based on Trichoderma spp. was found economically viable as indicated by incremental cost: benefit ratio ranging from 1:3.1 to 1:3.8 that was different with garlic clove extract (1:1.2 to 1:2.0), besides mustard seed was produced without any application of toxic fungicides.

Distal Digital Replantation

Hand surgeons have been hesitant to perform distal digital replantation because of the technical challenges and the perception of a high cost-to-benefit ratio. Recent studies, however, have shown high survival rates and excellent functional and aesthetic results, providing renewed enthusiasm for distal replantation. The authors reviewed the literature and summarize key points regarding the surgical treatment, perioperative care, and outcomes of distal digital replantation. They describe specific techniques and considerations for surgical repair in each of four distal zones as described by Sebastin and Chung. Zone 1A replantation involves an artery-only anastomosis of a longitudinal pulp artery. Venous anastomosis first becomes possible in zone 1B. Zone 1C involves periarticular amputations where arthrodesis of the distal interphalangeal joint is usually indicated. Repair of the artery, vein, and nerve is technically optimal in zone 1D, where venous anastomosis should be performed. Overall, survival rates for distal digital replantation are similar to those reported for more proximal replantation. The literature reports good outcomes regarding nail salvage, fingertip sensibility, and range of motion, with restoration of length and aesthetic appearance. Distal replantation performed at institutions that specialize in microsurgery and specifically tailored to the level of injury is associated with good survival, function, and patient satisfaction and superior aesthetic outcome. More prospective data are needed to evaluate the cost of treatment, psychological outcomes, and functional outcomes of distal replantation compared with revision amputation.

Valores biométricos obtidos por ultra-sonografia dos tendões flexores e ligamentos acessório inferior e suspensório da região metacárpica palmar de cavalos Mangalarga Marchador

Determinou-se a área transversal (AT) dos tendões e ligamentos da região metacárpica palmar de 15 cavalos da raça Mangalarga Marchador. As áreas transversais do tendão do músculo flexor digital superficial (TFDS), do tendão do músculo flexor digital profundo (TFDP), do ligamento acessório inferior (LA) e do ligamento suspensório (LS) foram determinadas mediante ultra-sonografia, em sete zonas distintas (1A, 1B, 2A, 2B, 3A, 3B e 3C). Os valores médios da AT para TFDS foram: zona 1A, 1,07±0,13; zona 1B, 0,97±0,12; zona 2A, 0,77±0,08; zona 2B, 0,68±0,12; zona 3A, 0,74±0,10; zona 3B, 0,86±0,10; e zona 3C, 1,33±0,24. Para TFDP foram: zona 1A, 1,09±0,12; zona 1B, 0,99±0,14; zona 2A, 0,72±0,11; zona 2B, 0,63±0,10; zona 3A, 0,71±0,14; zona 3B, 0,87±0,14; e zona 3C, 1,39±0,20. Para LA foram: zona 1A, 1,17±0,14; zona 1B, 0,85±0,11; zona 2A, 0,73±0,12; zona 2B, 0,60±0,16; e zona 3A, 0,42±0,15. Para LS foram: zona 1A, 0,82±0,14; zona 1B, 1,23±0,15; zona 2A, 1,21±0,15; zona 2B, 1,18±0,14; e zona 3A, 1,20±0,31. A AT de cada estrutura avaliada foi similar entre membros torácicos, considerando a mesma zona estudada. Não houve diferença significativa entre a AT do TFDS e a do TFDP.

Using chemometric tools to assess anthropogenic effects in river waterA case study: Guadalquivir River (Spain)

The Guadalquivir River is the major water source of the south of Spain. In this work, we have selected an area, about 115 km long, from Alcalá del Rı́o to the mouth of the river, to study the effects caused by human activities on water quality. The area under study includes several sensible points as the town of Seville, the Guadiamar River (where an important mine spill took place on April 1998) and the Doñana National Park. We measured several physico-chemical variables in the 26 sampling stations located along the river, and in three different campaigns from 2001 to 2002. With the results we built the data matrix, which was analysed by factor analysis/principal components analysis (FA/PCA) and cluster analysis (CA). This analysis allowed the identification of four different zones in the river, with different water quality. The first zone (zone 1A) comprised from Alcalá del Rı́o to Seville. The second zone (zone 1B) was the city of Seville, and as a consequence, presented higher concentrations of several variables such as nitrite, ammonium or manganese. The third zone (zone 2) included from Seville to the Guadiamar River. In this area, agriculture is the main activity, and then, higher concentrations of suspended solids and phosphate were measured. In terms of water quality, this zone was partially similar to zone 1A, and partially similar to the fourth zone, starting in the Guadiamar River and finishing in the mouth of the Guadalquivir River. The water in this last zone (zone 3) is mainly estuarine water. Thus, its quality is influenced by seawater input, and also by the inputs from the Guadiamar River (coming from a mining area), and presented higher copper concentration. Three principal components were extracted, explaining the 79.1% of the data variance. PC1 (46.9% variance) was mainly associated with nitrite, ammonium and manganese. PC2 (22.5% variance) was mainly associated with suspended solids and phosphates. PC3 (9.7% variance) was mainly correlated to nitrate and copper concentration.

Using chemometric tools to assess anthropogenic effects in river water: A case study: Guadalquivir River (Spain)

The Guadalquivir River is the major water source of the south of Spain. In this work, we have selected an area, about 115 km long, from Alcalá del Rı́o to the mouth of the river, to study the effects caused by human activities on water quality. The area under study includes several sensible points as the town of Seville, the Guadiamar River (where an important mine spill took place on April 1998) and the Doñana National Park. We measured several physico-chemical variables in the 26 sampling stations located along the river, and in three different campaigns from 2001 to 2002. With the results we built the data matrix, which was analysed by factor analysis/principal components analysis (FA/PCA) and cluster analysis (CA). This analysis allowed the identification of four different zones in the river, with different water quality. The first zone (zone 1A) comprised from Alcalá del Rı́o to Seville. The second zone (zone 1B) was the city of Seville, and as a consequence, presented higher concentrations of several variables such as nitrite, ammonium or manganese. The third zone (zone 2) included from Seville to the Guadiamar River. In this area, agriculture is the main activity, and then, higher concentrations of suspended solids and phosphate were measured. In terms of water quality, this zone was partially similar to zone 1A, and partially similar to the fourth zone, starting in the Guadiamar River and finishing in the mouth of the Guadalquivir River. The water in this last zone (zone 3) is mainly estuarine water. Thus, its quality is influenced by seawater input, and also by the inputs from the Guadiamar River (coming from a mining area), and presented higher copper concentration. Three principal components were extracted, explaining the 79.1% of the data variance. PC1 (46.9% variance) was mainly associated with nitrite, ammonium and manganese. PC2 (22.5% variance) was mainly associated with suspended solids and phosphates. PC3 (9.7% variance) was mainly correlated to nitrate and copper concentration.

P53 independent, region-specific epithelial apoptosis is induced in the rat epididymis by deprivation of luminal factors.

Luminal testicular factors are known to be important for the regulation of the epididymal epithelium. The present study was undertaken to test the hypothesis that complete deprivation of luminal factors by efferent duct ligation (EDL) would induce apoptosis in the epididymal epithelium, as does removal of trophic factors from other cell types. Additionally, experiments were performed to determine whether the apoptosis detected was p53 dependent or independent. Apoptosis detection was by terminal deoxynucleotidyl-mediated deoxyuridine triphosphate-biotin nick-end labeling and by DNA fragmentation studies. EDL caused loss of testicular luminal contribution in zone 1A of the rat epididymis (proximal initial segment) within 6 hr and induced epithelial apoptosis within 12 hr of the efferent duct obstruction. The wave of apoptosis in zone 1A was completed by three days after EDL and was followed by a much smaller wave in zone 1B which peaked three days after EDL. Significant apoptosis was not detected in any epididymal region distal to the initial segment for periods as long as 15 days after EDL. p53, a key apoptotic-pathway molecule in many tissues and conditions was tested by immunohistochemical and Western blot techniques and was not upregulated in the initial segment epithelium within the time cells were undergoing apoptosis and well before the wave of apoptosis was complete. It was concluded that epithelial apoptosis in the initial segment of the rat epididymis is induced by deprivation of luminal testicular factors, is localized to the proximal and middle initial segment, and is p53 independent.

Prudhoe Bay Field Study - Return Fluid Analysis

Summary. Monitoring ionic content of returned fluids after various acidizing treatments gives insight into actual chemical acid-spending processes that occur downhole. In this study, laboratory tests and field treatments were performed, and the resultant dissolution processes were monitored. Results show that the high siderite concentration (6 to 12 %) in the Sadlerochit formation accounts for most (60 to 70%) of the hydrochloric acid spending, as well as 10 to 15% of carbonate spending and 10 to 15% of clay dissolution during HF acid treatments. The HF spending was primarily on quartz/ chert in the laboratory. Field results, however, indicate that the secondary clay dissolution process was the primary HF spending reaction. Introduction The Prudhoe Bay field was discovered in 1968, and subsequent drilling confirmed that it was the largest oil and gas field in North America. The Prudhoe Bay Unit became effective on April 1, 1977, and began production on June 19, 1977, after completion of the Trans-Alaska Pipeline System. Since then, more than 750 wells have been completed in the Sadlerochit formation. Initial stimulation treatments were based on calcium carbonate scale removal and subsequent inhibitor squeezes. These treatments were quite effective in a high percentage of wells where scaling problems had been identified. In late 1984 and early 1985, HF acid treatments were started on the Sadlerochit formation to stimulate wells that did not respond to the established EDTA scale treatments. Since then, several HF acid treatments have been performed successfully. However, a greater understanding of downhole chemistry was needed to improve treating response even further. Several authors have presented laboratory studies on HF acidizing and the actual reactions occurring in various core types. Gdanski and Peavy presented a study on well return analysis and a method for calculating the actual downhole reaction with the specific ionic concentrations from fluids returned after a retarded-HF acid treatment. This paper describes a comprehensive study on acidizing in Zones 1B and 4 of the Sadlerochit formation. Mineralogy, solubility, oil, and acidizing chemistry studies were performed in the laboratory with Sadlerochit core samples to give an idea of the products that would be expected upon acidizing fluid return. Also discussed is the field study of several acidizing treatments and analyses of the actual returned fluids. Experimental Procedures Mineralogy. Mineralogy of the various core samples was analyzed by X-ray diffraction (XRD). An X-ray powder diffractometer was used on a bulk powder sample from Well 12–3. Acid Solubility Tests. In these tests, 1.00 g of disaggregated sample (from Well 12–3) was placed into 100.0 nit of either 15% HCl or 12 % HCl/3 % HF acid for 2 hours at 150 degrees F [66 degrees C] under a N2 gas blanket. Solubilities were determined by weight loss. Total iron content was determined by boiling the disaggregated sample with HCl acid containing H2O2. Extracted iron was determined by titration with dichromate. Dissolved-Solids Analysis. The supernatant fluids from the acid solubility tests were analyzed for dissolved solids contents. Cationic concentrations of Ca, Mg, Si, Ba, Al, Sr, Na, Fe, and K were determined from atomic absorption measurements. Total Fe concentrations on Well 12–3 samples were obtained from atomic absorption measurements; Fe3+ and Fe2+ concentrations were obtained spectrophotometrically. All concentrations are expressed in milligrams per liter. Returned Fluid Collection and Analysis. An elaborate collection scheme was implemented to perform a return fluid analysis. Samples of acids used to treat the formation or tubing were collected before the job to provide a known acid concentration and ionic content. When possible, a sample of the produced formation water was collected for ionic reference of the makeup fluid. Ions for which fluid was evaluated were Cl, SO4, Si, Fe (total Fe, Fe2+, and Fe3+), Ca, Al, K, Mg, Sr, Ba, Na, and F. Analyses for the specific ions were performed in a laboratory on the North Slope. In addition to the specific ion concentrations, a date, collection time, production rate, cumulative water production, water cut, pH, specific gravity, and live acid concentration of the returned samples were recorded. Mineralogy Return analyses-from two of the four production zones in the Sadlerochit formation (Zones 1B and 4, with the emphasis on Zone 4 wells) was completed. JPT P. 466⁁

Histological changes in lungs of calves exposed to an aerosol of Pasteurella haemolytica

An experiment was designed to study the interaction of Pasteurella haemolytica with an attenuated bovine herpesvirus 1 in calves. Low titre of the virus culture used for aerosol exposure failed to produce measurable interaction. However, the experiment provided the first opportunity to study the light-microscopic changes in lungs of calves (n=3) to a low-dose exposure (5-min aerosol) of P. haemolytica A1 from a fresh 5-h log-phase culture. The histopathological study was confined to tissue exposed to only P. haemolytica. A limited macroscopic pneumonia was produced in ventral parts of cranial lobes. Four days after exposure, a typical reaction featured four zones. Zone 1a at the centre with acute inflammatory processes and necrosis of phagocytic cells was surrounded by a broad band of compacted, largely necrotic macrophages and polymorphonuclear leucocytes (PMNL) in alveoli of zone 1b. Necrosis was confined to zone 1. Zone 2a frequently occupied the remainder of the lobule with irregular distribution of congestion, oedema with a fibrinous component, and infiltration by numerous PMNL, macrophages and other mononuclear inflammatory cells. The narrow zone 2b was located between zones 1b and 2a and had oedema with a fibrinous component, numerous fibrocytes, few inflammatory cells and empty capillaries. It is suggested that zone 2 served to isolate zone 1 by surrounding it with non-functional tissue. The pathogenicity of P. haemolytica is discussed for uncompromised lungs and lungs compromised by virulent BHV1 infection.

Late Quaternary vegetation and climate of southern Tierra del Fuego

Vegetation and climate over approximately the past 13,000 yr are reconstructed from fossil pollen in a 9.4-m mire section at Caleta Róbalo on Beagle Channel, Isla Navarino (54°56′S, 67°38′W), southern Tierra del Fuego. Fifty surface samples reflecting modern pollen dispersal serve to interpret the record. Chronologically controlled by nine radiocarbon dates, fossil pollen assemblages are: Empetrum-Gramineae- Gunnera-Tubuliflorae (zone 3b, 13,000–11,850 yr B.P.), Gramineae- Empetrum-assorted minor taxa (zone 3a, 11,850-10,000 yr B.P.), Nothofagus-Gramineae-Tubuliflorae-Polypodiaceae (zone 2, 10,000–5000 yr B.P.), Nothofagus-Empetrum (zone 1b, 5000-3000 yr B.P.), and Empetrum-Nothofagus (zone 1a, 3000-0 yr B.P.). Assemblages show tundra under a cold, dry climate (zone 3), followed by open woodland (zone 2), as conditions became warmer and less dry, and later, with greater humidity and lower temperatures, by closed forest and the spread of mires (zone 1). Comparisons drawn with records from Antarctica, New Zealand, Tasmania, and the subantarctic islands demonstrate broadly uniform conditions in the circumpolar Southern Hemisphere. The influences of continental and maritime antarctic air masses were apparently considerable in Tierra del Fuego during cold late-glacial time, whereas Holocene climate was largely regulated by interplay between maritime polar and maritime tropical air.