Collar Length Research Articles

Seedling Growth and Nutritional Status of Elaeagnus angustifolia and Robinia pseudoacacia as Response to Arbuscular Mycorrhizal Fungi and K-Humate

ABSTRACT This study aimed to reveal the effects of arbuscular mycorrhizae and K-humate on some of the morphological characteristics and growth of Russian olive (RO; Elaeagnus angustifolia L.) and black locust (BL; Robinia pseudoacacia L.). The indigenous mycorrhizal spores (Claroideoglomus claroideum, Claroideoglomus etunicatum, Claroideoglomus luteum, and Funneliformis mosseae) collected from rhizospheres of RO and BL trees in afforestation sites located in Central Anatolia. In addition, commercial mycorrhizal mixture and K-humate were used as treatments. Five treatments (1—indigenous mycorrhizal fungi, 2—K-humate, 3—indigenous mycorrhizal fungi + K-humate, 4—commercial mycorrhizal fungi, and 5—control) were assigned in a completely randomized design for both tree species. Four months after the treatments, inoculation rate, above-ground seedling height, fresh and dry weight, root collar diameter, length, fresh, and dry weight, leaf area index, shot-to-root dry weight ratio, seedling height to root collar diameter ratio, and Dickson quality index were determined. Plant and soil analyses were carried out to determine the effects of treatments on plant and soil nutrition. Indigenous arbuscular mycorrhizal fungi and K-humate combinations had positive effects on the morphological characteristics and nutritional status of the seedlings. The indigenous mycorrhizal and K-humate interaction showed the most pronounced effects on RO growth and nutrition.

Characteristic Morphology and Biomass Production of Napier Grass (Pennisetum purpureum) Cultivar Gama Umami Under Teak Tree (Tectona grandis) Shade in Blora, Central Java

This study aims to determine the characteristic morphology and biomass production of Napier grass (Pennisetum purpureum) cultivar Gama Umami under teak tree (Tectona grandis) shade in teak tree forest area of Blora, Central Java. The grass was planted using stem cuttings and maintained for four months using the randomized block design (RBD) method with six repetitions in each treatment. This study consisted of two treatments, namely shade under teak tree stands and non-shade or open area as a control. Maintenance was carried out for 14 weeks with the addition of fertilizers, such as NPK (nitrogen, phosphor, and potassium) and urea. Parameters measured included plant height, leaf length, leaf width, first collar length, number of tiller, and stem diameter. After 14 weeks the plants were harvested, and biomass production data were obtained. The results showed that there were no differences in leaf length, leaf width, first collar length, number shoots, and stem diameter between under the shade and non-shade of teak trees. However, the plant height and biomass production of Napier grass cultivated in non-shade teak trees were higher than under the shade of teak trees. The finding showed that Napier grass cultivar Gama Umami could be cultivated under the shade of teak tree forest and introduce for silvopasture system in teak trees forest area.

Characteristics and mechanism of local scour reduction around spur dike using the collar in clear water

To reduce the local scour around the spur dike, the U-shaped collar is proposed in this study. The influence of the collar's length, width, and porosity on the local scour reduction in clear water is studied by model tests and numerical simulations. Experimental studies show that the collar has a significant effect on reducing the local scour. The location of the maximum scour depth of the spur dike moves downstream. The width of the collar has the greatest impact on the reduction effect among the three selected factors, followed by the porosity and the length. Local scour reduction efficiency of the collar can reach 56.9%. Based on the regression analysis of the range and variety, a formula for predicting the reduction effect around the spur dike is put forward, and the deviation between the values by formula and that in experiments are within ± 4%. The characteristics of the flow field around the spur dike under constant conditions with a collar are studied via numerical simulation. The numerical simulation results show that compared to the case without collar, the flow velocities around the spur dike in cases with permeable collar and solid collar reduced by 45% and 25%, respectively, and the shear stresses reduced by 20% and 28.6%, respectively. The results of this study can provide a reference for local scour reduction using the solid collar or collar made of permeable materials such as gabions.

Early Radiographic Fit and Fill Analysis of a New Metaphyseal-Filling Triple Taper Stem Designed Using a Large Computed Tomography Scan Database.

Numerous cementless stems are available to maximize implant stability, fit, and survivorship in total hip arthroplasty. Recently, a new metaphyseal-filling triple-taper collared stem was designed using femoral morphology data obtained from over 1300 computed tomography scans. The purpose of this study was to evaluate the radiographic fit and fill of this new stem in the coronal and sagittal dimensions. In this retrospective review, postoperative radiographs of patients receiving this new stem were analyzed in accordance with previously published fit and fill analyses. All radiographs were taken 6weeks postoperatively. Means and standard deviations were reported for all fit and fill parameters. Fifty-nine hips were analyzed from 55 patients undergoing total hip arthroplasty. The coronal proximal fill was 85.02 ± 8.06%, and coronal distal fill was 75.21 ± 9.71%. The sagittal proximal fill was 86.51 ± 8.77%, and sagittal distal fill was 59.17 ± 8.66%. Mean calcar collar coverage was 80.64 ± 19.6% and all patients had full seating of the collar. Six cases (10.2%) had a collar length greater than the calcar length, with a mean collar overhang of 0.7 ± 0.4 mm. This new stem demonstrated significant proximal fill in both the coronal and sagittal planes and validates the design intent of this implant. This is the first study to evaluate sagittal fit and fill of a femoral stem. Long-term follow-up is required to understand the clinical impact these fit and fill characteristics may have on patients' long-term outcomes.

Enhancement of Open-Ended Pipe Pile Embedded in Sand Using Steel Collar

The open-ended pipe piles are among the piles that are employed the most frequently because of their advantages, including their ease of transport and resistance to driving stress. It is further distinguished by the fact that the soil column formed inside the pile increases the pile capacity. Numerous ideas have been presented forth in the literature to enhance the performance of these piles. In this study, it is suggested that a steel collar be used at its lowest end to enhance the performance of the pile. Ten experimental tests for piles embedded in loose sand soil were carried out to determine the impact of the collar diameter and length concerning the pile diameter and length. Three diameters, 1.5D, 2D, and 3D, and three length ratios: 10, 20, and 30% were employed. The use of a steel collar improves the load capacity of the pile and reduces settlement, according to the data, although the collar with a diameter of 1.5D and a length of 10% had little effect. According to the study, using a collar with a diameter of 2D and a length of 20% is enough to double pile capacity and prevent the overlapping effect of stress bulbs between neighboring piles. As a result, using such a method minimizes the cost of constructing the foundations because of the reduction in the number of piles required.

Investigating survival/growth ratio of scots pine (Pinus sylvestris L.) afforestation efforts and effects of BUROR terracing operations on some soil properties in the lands susceptive to soil erosion in Erzincan

Erzincan-Keklik kayası mevkiinde yürütülen bu çalışmada, 2012 yılında, BUROR mini-ekskavatörle teraslama sonrası uygulanan ağaçlandırma ve erozyon kontrol faaliyetlerinde dikilen sarıçam fidanlarının 2018 yılı vejetasyon dönemi sonundaki (6 yıllık) gelişim durumlarının değerlendirmesi yapılmıştır. Bu amaçla, dikimlerin yapıldığı alandan 20 m x 20 m büyüklüğünde (yaklaşık 400 m2) toplam 7 deneme parseli seçilmiş ve her bir parselde rasgele tespit edilen 30 (toplamda 210 adet) fidanın boyu, kök boğazı çapları ve dikimden bu yana geçen her bir vejetasyon dönemine ait yıllık boy artımları ölçülmüştür. Ayrıca, söz konusu bu ağaçlandırma ve erozyon kontrol faaliyetlerinin toprakta neden olduğu olası bazı fiziksel ve kimyasal değişimleri tespit etmek üzere de 42 tanesi dikim yapılan terasların içinden (fidan dibinden), 29 tanesi ise terasların aralarından (doğal/kontrol alan) olmak üzere toplamda 71 bozulmuş toprak örneği alınarak pH, organik madde (OM), elektriksel iletkenlik (Eİ), agregat stabilitesi ve tekstür değerleri için analize tabi tutulmuşlardır. Araştırma sonucunda, altı yıllık büyüme dönemi sonunda, dikilen sarıçam fidanlarında %88’lik bir başarı oranı yakalandığı, ortalama kök boğaz çaplarının ise 47.3 mm’ye ulaştığı belirlenmiştir. Bununla beraber, güney bakıdaki yamaçlarda dikilen sarıçam fidanlarının ulaştıkları ortalama 130.3 cm’lik boy ile kuzey bakıdakilerden (120.9 cm) istatiksel olarak daha uzun oldukları tespit edilmiştir. Toprak analiz verileri üzerindeki değerlendirmelerde ise mini ekskavatörle yapılan BUROR terasların bazı toprak özellikleri üzerinde negatif etkiler yarattığı ve kısmen bozulan bu özelliklerin doğal değerlerine ulaşmasının zaman alacağı sonucuna varılmıştır. Son olarak, bu araştırmanın önemli sonuçlarından birinin de 2013 ile 2018 büyüme dönemlerindeki sarıçam boy artımlarıyla hem bir önceki yıl yağan toplam yağış miktarları (R2 = 0.77) hem de vejetasyon dönemindeki yağış miktarları arasında (R2 = 0.85) yüksek bir ilişki olduğunun tespit edilmesi olmuştur.

Where to draw the line? Understanding preferences in mucosal collar length after circumcision: A crowdsourced survey from the U.S. general population.

Male circumcision is a polarizing and prevalent procedure. Little understanding exists regarding patient preferences for circumcision appearance. Our objective was to elicit how mucosal collar length may be perceived in terms of overall cosmesis and desirability among adults. A questionnaire using REDCap was created and distributed through Amazon Mechanical Turk. Respondents provided demographic information and circumcision status before being challenged with artistic representations of circumcised penises with increasing lengths of mucosal collar. Participants were asked to select the most and least esthetically pleasing image, as well as rate the "importance of appearance" from 0-100. Responses were analyzed with ordinal regression models. Preference for shorter mucosal collars were seen in respondents with a postgraduate education (p=0.013) and no religious affiliation (p=0.034). In contrast, participants reporting a religious affiliation preferred longer mucosal collars (p=0.034). Circumcised males rated appearance as being more important (p=0.001) in contrast to uncircumcised males who did not (p=0.001). Circumcised fathers were more likely to circumcise their sons relative to uncircumcised fathers (p<0.05) and women preferred circumcision (p<0.05). Our study revealed polarized esthetic preferences in the sample as a whole, with large proportions of respondents selecting the longest or shortest collar length. Preferences regarding mucosal collar length appear to be most influenced by education and religion. Overall, our study did not observe a predominant preference for mucosal collar length following circumcision. Surgeons should engage patients and/or caregivers/parents preoperatively in discussions regarding preferences and desired cosmetic outcomes.

Effects of nitrogen rate on growth and quality of rapeseed blanket seedling for mechanized transplanting

Cultivating a high quality rapeseed blanket seedling is crucial if the mechanized transplant of rapeseed is to become an effective part of oilseed production in China. Nitrogen (N) strongly affects the growth and quality of the rapeseed seedling. This study investigated the agronomic traits, physiological indexes, the surviving number of blanket seedlings, and the survival rate after transplanting two canola (Brassica napus L.) cultivars (Ningza 1838 and Yangyou 9) treated with five N rates (0, 0.5, 1.0, 1.5 and 2.0 g N per tray). Plant height, leaf age, leaf area, collar length, fresh and dry weights, moisture content, and N concentration in root and shoot all increased as the N rate increased. The survival number, collar diameter, root to shoot ratio at the 30th day after sowing and the survival rate at the 10th day after transplanting increased at first then decreased as N rate consecutively increased. The survival number and survival rate under the 1.0 and 1.5 g N per tray treatments were most improved amongst N treatments, although there was no significant difference between these two N treatments. This suggests that to achieve high-quality blanket seedling needed for mechanized transplanting, the application of N at rates of 1.0 to 1.5 g N per tray at the one-leaf and one-heart stages is recommended.

Where to Draw the Line: Understanding Preferences in Mucosal Collar Length After Circumcision

ABSTRACT Introduction Male circumcision is a polarizing and omni prevalent procedure within the United States (U.S.). Little understanding exists regarding patient preferences for circumcision appearance. Objective To illicit how mucosal collar length may be perceived in terms of overall cosmesis and desirability amongst adults. Methods A questionnaire using REDCap was created and distributed through Amazon Mechanical Turk. Respondents provided demographic information and circumcision status before being challenged with artistic representations of circumcised penises with increasing lengths of mucosal collar. Participants were asked to select the most and least aesthetically pleasing image as well as rate the “importance of appearance” from 0 to 100. Responses were analyzed with ordinal regression models. Results Preference for shorter mucosal collars were seen in respondents with a postgraduate education (P = 0.013) and no religious affiliation (P = 0.034). In contrast, participants reporting a religious affiliation preferred longer mucosal collars (P = 0.034). Circumcised males rated appearance as being more important (P = 0.001) in contrast to uncircumcised males who did not (P = 0.001). Women were neutral (P = 0.199). Black or African American participants valued circumcision appearance more (P = 0.020) than Caucasian participants (P = 0.021). Conclusions Preferences regarding mucosal collar length appear to be influenced by education and religion. Overall, our study did not observe a predominant preference for mucosal collar length following circumcision. With this in mind, surgeons should engage patients preoperatively in discussions regarding preferences and desired cosmetic outcomes. Disclosure No

Investigation on axial-lateral-torsion nonlinear coupling vibration model and stick-slip characteristics of drilling string in ultra-HPHT curved wells

In view of the vibration failure of drilling string system in ultra-high temperature and high pressure (ultra-HPHT) curved wells, an axial-lateral-torsion coupling (ALTC) nonlinear vibration model of drilling string system was established using energy method and Hamiltonian principle, in which, the influence of wellbore trajectory change, wellbore constraint, interaction between bit and rock and ultra-HPHT of wellbore on elastic modulus and viscosity of drilling fluid were taken into account. The finite element method (FEM) is used to realize the numerical solution of the nonlinear vibration model. The correctness and validity of the ALTC nonlinear vibration model was verified by comparing the measured data of four ultra-HPHT wells with the theoretical calculation results of the proposed model.Based on this, according to the parameters of M directional well in Ledong ultra-HPHT block, South China Sea, the influences of ground rotation speed, drilling string length, weight on bit (WOB), torsional impact tools and drill collar length on stick slip vibration characteristics were investigated, and the method of increasing drilling speed in ultra-HPHT curved wells was put forward. The results obtained demonstrate that, firstly, when other requirements were met, the rotary speed should be increased as much as possible, which can effectively improve the drilling efficiency. Secondly, with the increase of drilling depth on-site, the drilling efficiency will be reduced, the whirl phenomenon of drill string system will be intensified, and the service life of bottom hole assembly (BHA) will be reduced. Thirdly, the optimized parameters of WOB and the torsional impact tool depended on the well structure, downhole tool size, etc. and can be determined using the proposed analysis method. The research results provide a theoretically sound guidance for designing and practically sound approach for effectively improving rate of penetration (ROP) and the service life of drilling string in ultra-HPHT curved wells.

Domestication of “Deguai” (Saurauia bontocensis Merr.) at La Trinidad, Benguet, Philippines

“Deguai” (Saurauia bontocensis Merr.) is an indigenous wild fruit-bearing tree in the Cordillera Administrative Region (CAR), Philippines. Due to rampant and continuing conversion of its habitat into agricultural and other uses, its population has become low, and its distribution has narrowed considerably. Thus, conserving and domesticating this endemic species by establishing propagation techniques and mini-tree plantations is timely and crucial. Results showed that deguai could be readily raised by sowing fresh seeds in heat-sterilized loam soil without pre-germination treatments. It took 22 d from sowing to start and 48 d to end the germination, with a mean germination percentage of 39.60. Moreover, transplanted seedlings in various media combinations showed significant growth differences in root collar diameter (RCD) and length of primary and secondary roots but not on their height and number of secondary roots. Compost in combination with either topsoil or sand significantly emerged as the most suitable media for the growth of the studied seedlings. Stem cuttings grew best untreated rather than applying rooting hormones such as alpha-naphthalene acetic acid (ANAA) and Hormex. This result was manifested in the significantly high survival rate, numerous developed buds, and longest newly developed shoots of untreated cuttings. Stem cutting section treatment significantly affected the number of developed buds only, where base cuttings had the most. The mini-tree plantation established using rooted stem cuttings was successful with a high survival rate of 89.26% after 5 yr from field planting and with four deguai trees bearing fruits for the first time after 7 yr from field planting. The nursery-grown seedlings planted in the mini-tree plantation have exhibited a 99% survival rate nine months after outplanting. Thus, deguai can be domesticated in the new habitat for fruit production, improvement of the environment, and biodiversity conservation. Monitoring of the trees continues, and a study toward generating a fruit production-enhancing technique for the species is readied for implementation.

Effect of Root Pruning on the Root Growth Potential (RGP) of Three Philippine Native Tree Species

Root growth potential (RGP) is the plant’s capacity to grow new roots, an important trait for seedlings to be used on any reforestation program. In the Philippines, these kinds of programs often end up in failure, as low-quality seedlings are usually chosen due to unfamiliarity with attributes that indicate good outplanting performance, narrow sources of high-quality seeds, and the lack of a reliable quality assessment method. This study aimed to determine the RGP of three native species – namely, bignai (Antidesma bunius), kamagong (Diospyros blancoi), and molave (Vitex parviflora) – and find its correlation with other morphological parameters. The experiment was done in a completely randomized design (CRD) with taproot pruning lengths (1-cm pruning, 2-cm pruning, and no root pruning) applied as treatments for each species. The morphological parameters measured included the relative growth rate (height and diameter), number of leaves, root collar diameter (RCD), biomass (root, shoot, and total) and length of taproot while root-shoot ratio, sturdiness quotient, and seedling quality index (SQI) were calculated. In general, taproot pruning had no significant effects on the seedling morphological attributes of all species. Excluding molave, the two other species had mostly responded well to root pruning and can be recommended as a treatment to induce root growth development. RGP had generally complemented the results from the other parameters, indicating how root development was associated with the morphological growth of the species. The study shows how RGP can also be relied on for testing seedling health and the status of native species. For a more comprehensive result, future research could increase experiment duration or use younger seedlings. A field performance assessment could also be performed to supplement the RGP study

Countermeasures Against Local Scouring Around Bridge Abutments: Combined System of Collar and Slot

An important issue in river engineering is to control scour around bridge piers and abutments using either a collar or a slot. This study examines the use of a slot or a collar, either alone or in conjunction with one other, to reduce scour at bridge abutments. In research on abutments equipped with slots only, collars only, and a combination of both were tested 15, 9, and 18 times, respectively. According to the results, in abutments equipped with slots only, the closer the slot is to the channel wall, the better the performance. At the same time, according to the results of research on collars, mere protection of the upstream face of the abutment is not sufficient to prevent down flows due to the presence of horseshoe and wake vortices, but the downstream faces of collars play a substantial role in reducing scour. With an increase in collar length, the scour depth decreases and the scour hole shifts downstream farther away from the abutment. Finally, it was found that the slot–collar combination model takes a more proactive role in reducing scour compared to collars only or slots only. The most robust combinatorial model used managed to fully control scour around abutments. For combinatorial models, scour showed a 42–100% decrease under different flow conditions in an erodible bed.

Numerical parametric study on three-dimensional rectangular counter-flow thrust vectoring control

Recently, fluidic thrust vectoring control is popular for micro space launcher propulsion systems due to its several advantages, such as fast dynamic responsiveness, better control effectiveness, and no moving mechanical equipment. Counter-flow thrust vectoring control is an especially effective technique by utilizing less suction flow to control the mainstream deflection flexibly. In the current work, theoretical and numerical analyses are performed together to elaborate on the performance of the three-dimensional rectangular counter-flow thrust vectoring control system. A new propulsion nozzle of Mach 2.5 is devised by method of characteristics. To testify the feasibility and accuracy of the present research methodology, numerical results were validated against experimental data from the open literature. The computational result using the standard k-epsilon turbulence model reveals a good match with experimentally measured static pressure values along the centerline of the upper suction collar. The influence of several key parameters on vectoring performance is investigated herein, including the mainstream temperature, collar radius, horizontal collar length, and gap height. Critical parameters have been quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, pitching angle, suction mass flow ratio, and thrust coefficient. Furthermore, the flow-field features are qualitatively expounded based on the static pressure contour, streamline, iso-turbulent kinetic energy contour, and iso-Mach number contour. Some important conclusions are offered for further studies. The mainstream temperature mainly affects different dynamic characteristics of the mixing shear layer, including the convective Mach number of the shear layer, density ratio, and flow velocity ratio. The collar radius influences the pressure gradient near the suction collar surface significantly. The pitching angle increases rapidly with the increasing collar radius. As the horizontal collar length increases, the systematic deflection angle initially increases then decreases. The highest pitching angle is obtained for L/ H = 3.53. With regard to the gap height, a larger gap height can achieve a higher pitching angle.

Local joint flexibility of CHS X-joints reinforced with collar plates in jacket structures subjected to axial load

This paper aims to investigate the local joint flexibility (LJF) of tubular X-joints with collar plates subjected to axial load. A total number of 136 FE models were generated and analyzed to investigate the effect of collar plate size and joint geometry (η, τc, β, γ, and τ) on the local joint flexibility factor (fLJF). Also, the weld profiles and the contact between the chord wall and the collar plates were modeled in the numerical simulations. Results showed that the increase of the collar plate thickness and length results in the decrease of the fLJF. Despite the difference between the fLJF of unreinforced and collar plate reinforced X-joints, there has not been any study on the fLJF of the X-joints reinforced with collar plate. Also, there is no design equation for determining the fLJF of the collar plate reinforced X-joints. Thus, the results of the parametric study were used to develop a design formula, to determine the fLJF of X-joints reinforced with collar plates under axial load.

A fuzzy logic apparel size decision methodology for online marketing

Purpose Beside the development of technology and accessibility, ease of use, ability to reach various products and compare many products at the same time make online shopping even more popular. Despite the great advantages provided by online shopping for either consumers or retailers, there are certain issues that must be solved to improve online shopping advantages. Finding right size is one of the biggest barriers against apparel online retailing. Since the use of apparels is directly related with fitting, choosing right size is becoming more critical for retailers and consumers. The purpose of this paper is to contribute to the solution of the problem. Design/methodology/approach For the study, the specific size measurements of male shirts (collar, shoulder, chest, waist, arm length in cm) from four different sizes (small, medium, large, x-large) and from eight different brands were collected and stored in a database. Totally, weight, height and body measurements (collar, shoulder, chest, waist and arm length in cm) of 80 male candidates, between the ages of 18 and 35, were measured individually. These data were then used for experiments. Findings Any product with known measurements can be compared with users’ body measurement based on fuzzy logic rule and the best-fitted size can be selected for users. Similarly, using the proposed web design, users are able to see desired products on users with similar body type. Originality/value In this study, a new mathematical method based on fuzzy relations for apparel size finder is proposed. Beside, this method can group users based on body measurements in order to find people with similar size.

Systematic analysis of factors that cause loss of preload in dental implants

Screw loosening is the most common factor associated with dental implant failure. One of the major cause for screw loosening is the “loss of preload”. Several factors including screw geometry, material properties particularly stiffness, surface texture and condition of mating surfaces, degree of lubrication, rate of tightening, integrity of joint etc.Objective:This review analyses the factors that are responsible for the loss of preload.Material and Methods:Screw geometry, Implant- Abutment Connection type (external hexagon platform, morse taper), Material properties viz Stiffness, Resilience, Materials viz gold, titanium, titanium alloy, Surface texture of the abutment screw, Condition of mating surfaces, Lubrication, Torque value, Rate of tightening (10, 20, 35N and retorque after 10mins) are taken into consideration in this study. The MEDLINE-PubMed database was searched from September 2016 to 10 years previously. Several journals were hand searched and from cross references. The outcome analysed are the factors that are responsible for loss of preload.Results:The search yielded 84 articles. After excluding duplicated abstracts and applying the inclusion and exclusion criteria, 36 studies were eligible for analysis. The result shows that loss of preload can occurs depending upon the type of material used, torque method, torque sequences, abutment connection type, influence of lubrication, abutment collar length. However we detected some potential limitations in the studies selected, mainly a minimum number of samples used for the study. Hence we suggest further studies to guarantee an excellence in methodological quality.Conclusion:Based on the available data it can be summarized that the knowledge of preload loss must be known for the clinicians to avoid such screw loosening and subsequent implant failure.

Investigation of planting age farm on saffron characteristics and corm position in soil, Kashmar, Iran

To evaluate the morphological characteristics and yield of saffron in the fields with ages over 4 years, we conducted random sampling from 3 fields with 3 ha area. For this purpose, we collected three samples from each of the fields with 4, 7 and 14 years old. Sampling depth was from 35 cm with minimum 5 bunches of plants harvested in each sample. Then the samples were transported to the laboratory in Ferdowsi University of Mashhad and all characteristics were determined and recorded such as leaf dry weight, number of daughter corms plant-1, average weight of corms, corms position in depth, collar length, leaves length, leaves diameter, number of leaves and stigma and flower yield of saffron in the field. Results showed that leaf length, collar length and the number of corms weighing between 1 to 3 g field-1 (from 7 to 14 years old) had significant differences (p≤0.05) compared to the 4-year-old field. Also, the number of leaves and corms weight increased with aging field (from 4 to 7 years) but these criteria decreased significantly (p≤0.01) with increased farm age (from 7 years to 14 years). Studies showed that the flower and stigma yield of the older farm (14 years), was not significant compared to the 7-year-old farm, but these criteria had a significant difference from 4- to 14-years-old farms. It seems to reduce tillage operations and for decreased losses of daughter corms for uses of propagation, and the dry fodder in summer, had no difference between efficiency of oldest farm (14 years) or 7-year-old farm.

An Analysis of Common Drill Stem Vibration Models

Excessive drill stem (DS) vibration while rotary drilling of oil and gas wells causes damages to drill bits and bottom hole assemblies (BHAs). In an attempt to mitigate DS vibrations, theoretical modeling of DS dynamics is used to predict severe vibration conditions. To construct the model, decisions have to be made on which beam theory to be used, how to implement forces acting on the DS, and the geometry of the DS. The objective of this paper is to emphasize the effect of these assumptions on DS vibration behavior under different, yet realistic, drilling conditions. The nonlinear equations of motion were obtained using Hamilton's principle and discretized using the finite element method. The finite element formulations were verified with uncoupled analytical models. A parametric study showed that increasing the weight on bit (WOB) and the drill pipe (DP) length clearly decreases the DS frequencies. However, extending the drill collar length does not reveal a clear trend in the resulting lateral vibration frequency behavior. At normal operating conditions with a low operating rotational speed, less than 80 RPM, the nonlinear Euler–Bernoulli and Timoshenko models give comparable results. At higher rotational speeds, the models deliver different outcomes. Considering only the BHA overestimates the DS critical operating speed; thus, the entire DS has to be considered to determine the critical RPM values to be avoided.

Uniformization of a Once-Punctured Annulus

The universal cover or the covering group of a hyperbolic Riemann surface \(X\) is important but hard to express explicitly. It can be, however, detected by the uniformization and a suitable description of \(X\). Beardon proposed five different ways to describe twice-punctured disks using fundamental domain, hyperbolic length, collar and extremal length in 2012. We parameterize a once-punctured annulus \(A\) in terms of five parameter pairs and give explicit formulas about the hyperbolic structure and the complex structure of \(A\). Several degenerate cases are also treated.