bluuebunny/crossref_metadata_2025 huggingface dataset:
Appraising the Development Potential of Ekofisk Over Tor Formation in the Halfdan Field, using a Multi-Disciplinary Approach to Well Planning and Applying Advances in Technology to Enhance Well Placement, Completion, Productivity and Recovery
Authors: Andreev Anton , Pitts Michael , Hoover Andrew , Elhassan Eyad Mohamed , Bexkens Felix Sebastian , Datta Sudipto , Singh Amit , Lund Espen , Panos Gomez Luis
Published: March 2021

Demonstrating a viable development for the Ekofisk reservoir directly above the producing Tor reservoir in the Halfdan Field (Danish North Sea) has historically been challenging. A recent well shows the value of cross-disciplinary collaboration and new technology to maximize recovery and mitigate reservoir and drilling risks. Specifically, 4D seismic was utilized when planning the well, while placement was optimized by using advanced geosteering tools. Well optimization was further enhanced by adopting novel completion and stimulation technologies.

Pressure data and 4D seismic show that Tor and Ekofisk are in dynamic communication, but the degree of communication varies locally. The integration of 4D seismic with other disciplines’ input succeeded in optimizing the well placement and narrowed the significant pore pressure uncertainty along the 12,000-ft reservoir section.

To maximize well length within the target zone and reduce the risk of being faulted out of the target reservoir deep resistivity was used to steer the well in the optimal layers. This contributed to 99% of the reservoir section being placed in the target zone.

Lessons learnt from an earlier appraisal well and modest production experience in this part of the Ekofisk reservoir helped to justify the choice of selective completion zones (Sliding Side Door) in the inner part of the horizontal drain in order to minimize the impact of potential water or premature water breakthrough from high-rate injection wells located in the underlying Tor reservoir. This decision was validated after drilling the inner part of the well, where water-swept zones were encountered in the heel, followed by a long gas pay zone in line with 4D seismic signal in the remainder of the inner well section.

To mitigate the risk of an unwanted fracture connection and increase contact with the tight oil-saturated reservoir, a novel stimulation and completion technology was successfully deployed in the outer 6-inch open-hole section of the well. The acid needles completion, deployed across a 3,000-ft reservoir interval and comprising 224 needles deployed by pumping acid, was the first installation of its kind in the Danish North Sea. For the acid needles completion, this installation holds two distinctions: the largest number of acid needles installed in a well, and the combination of the acid needles completion with a different completion system in a single lateral for the first time.
Holistic Approaches in Achieving Best in Class BIC Detailed Well Design and Operation Execution — The New Norm
Authors: Mhd Yusof Muhammad Hatta , Khalid M Zulfarid , A. Halim Rahimah , Ahmad Fauzi Nurfaridah , Sella Thurai Ahgheelan , Omar Ahmad Faiz , Alwi M Fairuz , Sulaiman M Zarkashi , Muslim Fadhli Adlan , Fabian Oka , A. Bakar Mohd Faiz , Lee Magdelene Jia
Published: March 2021

This paper will discuss the case study of two (2) projects in Malaysia that were stretched-to-limit and optimized ‘on-paper’ all the wells’ related engineering design and construction, operation activities pre and during drilling campaign as well as logistic arrangement, which led to significant cost reduction in wells and thus improving the overall project economics. This significant savings achieved with full compliance to technical standards as well as with the betterment to improve HSE during offshore execution.
Precise Bottom Hole Pressure Management to Reach Target Depth in a Narrow Windowed Ultra HP-HT Well: A Case for Automated Managed Pressure Drilling
Authors: Khalid Ali , Ashraf Qasim , Luqman Khurram , Hadj Moussa Ayoub , Ghulam Nabi Agha , Ahmed Baig Umair
Published: March 2021

With the energy sector in crisis the worldover, oil and gas operators continue to seek more effective and efficient methods to reach potential prospects. With sharply declining oil prices, it is imperative that operators minimize the non-productive time in the drilling of all wells.

Many operators are actively seeking riskier exploration to establish a strong foothold in this volatile market. One such area of interest to operators is HPHT and beyond wells. An HPHT prospect carries a high-risk high-reward potential, therefore newer and advanced methods are being deployed to successfully drill and complete HPHT wells.

The Makran Coastal belt in south western Pakistan is one such area containing a potential Ultra-HPHT prospect. Many operators had attempted to drill about 9 wells in the locality but never managed to reach target depth due to drilling operations being plagued with a large number of problems. The drilling problems included high pressure influxes, stuck pipe while controlling influxes, circulation losses with high mud weights and ECD’s, differential sticking against permeable formations, inefficient bottom hole pressure control due to mud weight reduction with high temperatures and swabbing from the formation due to having an insufficient trip margin.

The operator was facing an extremely narrow drilling window in the target section. The maximum formation pressure was estimated to be around 2.29 SG while the maximum fracture pressure of the formation was estimated to be around 2.35 SG in EMW. It was abundantly clear that drilling with a conventional mud system would be impossible and impractical on all forthcoming wells.

As it was of paramount importance to precisely manage the wellbore pressure profile, the operator decided to apply managed pressure drilling on a candidate well. By applying managed pressure drilling techniques the operator expected to drill the section with an underbalanced mud weight and maneuver the bottom hole pressure just above the pore pressure line and thereby avoid circulation losses, detect influxes early on and control influxes without the need of ever shutting in the well, account for mud density variations with temperatures by executing an advanced thermal hydraulics model in real time, mitigate swabbing from the formation again by maintaining a constant bottom hole pressure while tripping, and finally ascertain the downhole pressure environment by conducting dynamic formation pressure tests.

The successful application of MPD enabled the operator to reach target depth for the first time in the history of the area. The paper studies the planning, design, and execution of MPD on the subject well.
A Client's Fit for Purpose Solutions in Well Abandonment
Authors: Yap Yun Thiam , Kumar Avinash Kishore
Published: March 2021

Typically, most of the well abandonment practice is reference to the recognized industry standards i.e. NORSOK, UK Oil & Gas and etc, and this is how the wells abandonment was carried out in the past. These practices however evolved/changed over time with lessons learnt and experiences and turn into a fit for purpose solutions for the Client.

The shift in international and local standards and regulations for a robust plug and abandonment approach has placed the need for a better and long lasting permanent P&A methodology.

Adhering to the existing industry standards in well abandonment is somehow not practical and not cost effective to be implemented in different part of the well, where there are major differences in local regulations, reservoir conditions, caprock thickness, well design philosophy and etc. The magnitude of abandonment cost increase is not at par with the risk reduction in long term hydrocarbon leakage. A fit for purpose solutions is recommended in closing the gap between cost and risk.

Due to the extremely varied well architecture between wells, the approach to permanent abandonment varies depending on casing sizes, presence of packers and no of casings present to the caprock area. On top of that, identifying the highest depth for a placement of cement plug will reduce on the amount of plugs to be placed, saving rig time and operational time. So far, 16 idle wells have since been permanently abandoned with the systematic approach of applying caprock restoration concept and reinstating the poor isolation across caprock areas with cement with the assistance of technology to the likes of perf-wash-cement, and hydro mechanical casing cutter. These wells have successfully been abandoned as per host authority standards.

This paper will explore a major local oil company’ approach to decommissioning of wells, in line with local regulations enforced, while ensuring a cost effective approach is applied in line with the available technologies.
Casing While Drilling Application: Changing Mitigation to a Performance
Authors: Ruzhnikov Alexey , AlHosni Fahad , Echevarria Edgar Garnica , Varela Rodrigo
Published: March 2021

Well construction process through the unstable formations prone to total losses, pack-off and water influx is challenging. The manuscript describes the casing while drilling (CwD) combined with stage-cementing tool as introduced solution, when the challenge was to ensure that torque limit is not reached while drilling and estimate the effect of CwD on curing total losses and bring the casing while drilling performance to the level of conventional drilling.

Introduction of CwD required extensive study of the potential torque while drilling as existing stage-cementing tools have low torque rating. Additionally, the casing fatigue may be a factor affecting the operations what lead to an introduction of magnetic particle casing inspection. The CwD bit design was adopted to the geological conditions based on best performance of the PDC bit, and originally selected drilling parameters were further optimized based on the result of the first runs. As the drilling of the well required utilization of mud cap for well control purposes, the mud recipes were adjusted to optimize the drilling performance and minimize the cost implication.

The proposed solutions allowed to eliminate the problem with wellbore instability and related stuck pipe events. Further the proper engineering of the drilling process allowed significantly increase the rate of penetration since the beginning of the implementation, when the drilling torque never reached the limit even at 7,000 ft depth.

The manuscript describes in detail the approach to make a proper design of CwD process focusing on prevention of existing problems and aiming to convert mitigation tool to a performance tool. Additionally, in details described the studied effect of CwD on curing total losses in highly fractured environment.
Cementing Solutions for Monobore Challenges
Authors: Loh Thien Yu , Duong Anh Tuan , Chong Woon Phin
Published: March 2021

Monobore cementation is defined as where a single production tubing size runs from the pay zone all the way to surface and is cemented in place. This type of well design greatly reduce rig time and cost. The challenge however is to achieve a good cement in the annulus as a well barrier and to have a clean internal tubing after the cementing job to allow for successful production of the well.

To achieve a clean internal tubing, a distinct bottom and top plugs were used as a means of mechanical separation. For fluids design, mud had to be thinned down prior to the cementing job and, a designed fiber based spacer system was used to physically scrub any mud-film sticking on the tubing walls. The centralizers and cement system were designed to allow for efficient displacement of mud and hence providing good overall placement and top of cement in the tubing-casing annulus. The cement in the annulus will be verified by pressure testing the annulus to 500 psi higher than previous shoe leak-off.

This approach was implemented for the campaign of six wells, all designed with 5-1/2in monobore tubing.

The bottomhole static temperature (BHST) of the well ranges from 300 to 350°F. The cementing system also had to be designed to cater to the challenge of this field, having CO2 as high as 60%, high temperatures, and a long open hole section that requires isolation and cement to set within a required timeframe. The cementing jobs were validated by no losses or gains during the job, floats holding at the end of the cementing job, differential pressure of cement prior to bumping the plug, density and pump rates executed as planned, accepted pressure test criteria of the annulus, output validation of cement contamination in pipe and annulus based on fluids and final well information. To further validate this system, the cement bond log was also run as part of the evaluation process and the cement log showed that zonal isolation was achieved. After the perforations, the perforation tool was pulled out to surface and the tool looked very clean with no signs of contaminated mud or cement around the tool.

We demonstrate how this unique cementing approach can be a solution for the challenges of monobore cementing and one of the biggest problems of monobore cementing in the industry.
Integration of Multiple Data to Improve Condensate Yield Prediction in Pailin and Moragot Field, Pattani Basin, Gulf of Thailand
Authors: Kawphoy Rampueng , Thatmali Phanat
Published: March 2021

The objective of this study was to improve the accuracy of condensate gas ratio (CGR) prediction in the Pailin and Moragot areas. Conventional method to predict liquid component reserves used only long-life condensate gas ratio (long-life CGR) from near-by production platform(s). The long-life CGR data are available in the mature production platforms which commonly takes 1-2 years to observe the decline trend so that there is no available data in the new drilled area and non-production area. This might cause inaccurate prediction of liquid reserves in the future platform especially in the platform locates far away from the mature production area. Multiple data which are basin modeling, geochemical data, drill-stem test, and batch-level production were analyzed and integrated to improve the accuracy of CGR prediction and understand geological reasons of high or low liquid production platform. These data can improve the confident level for CGR estimation in the non-production area and help identify potentially high liquid production platforms. The results show that the high liquid production in Pailin and Moragot fields related with the differentiation of source rock and migration process. There are three (3) separated trends in Pailin field and two (2) trends in Moragot field using geochemical data and basin modeling data. The local DST data has been integrated to confirm the extent of potentially high liquid production in several future platforms which locates in non-production area. Also, the updated production data has been re-visited to estimate the new CGR for the project located near-by production platform.
Saving 2.2 Days from Drilling in Hard and Abrasive Sandstone Formation with Innovative 360 Rolling Diamond Element Bit Technology
Authors: Ngo Vi Lan , Khobchit Wanwarang , Teerachotmongkol Teerawat , Mohammad Zayyan , Abbasgholipour Ali , Jiratawaree Sanyapong , Tungperachaikul Thanakorn , Amranand Sorawit , Soontarerat Apimuk , Akeratchataphun Yindee , Udomsak Adiruj , Chantimapong Atthawat
Published: March 2021

This project drilled in Sin Phu Horm field. The main challenge in this field is the formation. The 8.5-in section is designed to drill through the hard and abrasive sandstone formation (known as Nam Phong formation) with unconfined compressive strength (UCS) between 6,000 and 24,000 psi and peak up to 55,000 psi. Multiple bit runs and heavy set of Polycrystalline Diamond Compact (PDC) bits were observed in the offset wells with slow rate of penetration (ROP) and short intervals, which resulted in a high drilling cost. In the offset runs, the average interval was observed between 200 and 300 meters and average on-bottom ROP ranged from 2 to 8 m/hr. Worn cutters were the main dull characteristic in the offset PDC bits and the bits were pulled out of hole due to slow ROP. Due to the challenging formation, the goal was to increase the interval per bit run and ROP which resulted to reduce the number of bit trips and drilling cost.

Looking at the dull grading of the offset PDC bits, it was obvious that the slow ROP was caused by the cutters worn by the abrasive and hard Nam Phong formation. The fixed-cutter PDC bits were run in the offset wells and worn cutters were observed in the shoulder area. The worn portion of the cutter occurred only in the exposed side, while the portion in the cutter pocket remained intact. Utilizing the portion in the cutter pocket helps to prolong cutter life, increase the ROP, and bit life longevity. Thus, it can help to reduce undesired bit trips.

Based on the worn cutter observation, the new design of the 8.5-in PDC bit equipped with innovative 360 rolling cutter (RC) bit was proposed.

A comprehensive vibration simulation drilling parameters roadmap were provided to minimize shock and vibration.

Two bits were run with rotary steerable BHA to drill Nam Phong formation in the field. The first bit drilled 431 meters at an average ROP of 6.8 m/hr and the second bit drilled 391 meters at an average ROP of 5.5 m/hr. Two runs using the 360 RC bits drilled 822 meters in total of 1,236 meters entire interval of Nam Phong formation, which was equivalent to 66%, achieving the operator's goal while saving 2.2 days solely from two runs of RC bit. This success increased the operator's confidence to run 360 RC bits in the subsequent wells to reduce the number of bit trips and increase the ROP.

This paper will discuss the application and evolution of 360 RC bit, along with the result achieved by the bit fitted equipped with this cutter in Thailand onshore.
Creative and Collaborative Engineering Delivers the Fastest Well in an Upper Miocene Reservoir, Shallow Water Field in The Gulf of Mexico
Authors: Caballero Guillermo , Kandasamy Rajeswary , Vilchez Omar E , Larrea Luis , Santarini Francisco , Padilla Carlos M , Cordova Arturo , Ballesteros Joel
Published: March 2021

This paper will detail the engineering strategies utilized from design and planning stage up to and beyond the field execution stage which resulted in drilling the fastest well in a shallow water field, delivering superior drilling performance and successfully targeting the Upper Miocene (tertiary) reservoir in Mexico.

From the 9 wells drilled in this field, the fastest well "Y"-200 was drilled with an average well construction index of 179 m/day when compared to the field average of 54.2 m/day. This shallow water field manifests several specific challenges which include tough drilling conditions, fluid property and hydraulic management, logging constraints and critical selection of casing setting depths.

In order to enhance the drilling performance results to lower costs and improve production timelines, the project team performed a deep-dive into the well challenges and engaged with multi disciplinary teams and service providers to brainstorm different design improvements and operational practices. By doing so, the performance accelerates the 6000 to 9000 bbls of initial production estimated per well.

The application of these creative engineering ideas proves that change, when applied correctly can really create lasting and proven improvements in drilling performance.
Boosting Up for Brown Field Oil with Well Placement and Drilling Engineering Synergy
Authors: Azmi Nur'ain Zalia , Rahman Rasheed , Shaibudin Eliyana , Lew Jason , Chew Danny , Alang Khairul Anuar , Za'ba Muhammad Afiq , Mustapa SyaifulAzman
Published: March 2021

X-Field is a mature offshore field located in the Sabah Basin, Malaysia. Two horizontal oil producers and one horizontal water injector was planned as part of the recent infill drilling campaign. As fields continue to mature, redevelopment projects often face both economical and technological challenges. Part of the redevelopment plan included the optimization of production and minimization of the residual/remaining attic oil in the reservoir.

The horizontal well placement approach combined with drilling engineering concepts was synergized to handle the subsurface and drilling challenges. There are many key subsurface uncertainties when drilling horizontal wells, including but not limited to discontinuous sand bodies, lateral variations in sand thicknesses, multiple layering or sand/shale pockets, rapid structural changes, and fluid contact variation.

In the planning stage, a systematic drilling engineering approach in managing drilling risks including complex anti-collision analysis contributed to successful drilling performance driven by "on-target" well placement execution. Selection of well placement technologies such as high definition multilayer-boundary mapping technology and wellbore imaging tool had enabled proactive geosteering to optimize the reservoir targets. This paper demonstrates the synergy of the drilling engineering and well placement technology selection, which was proven as a fit-for-purpose solution to deliver success to this horizontal well campaign in maximizing the production and injection potential.
Malaysia Integrated Rig Sequence - The Benefits and Challenges
Authors: Abd Wahab Abdul Aziz , M Ramli Syamsul Ariffin , Long M Noor Affendi Long M , Heong Mee Yee
Published: March 2021

Based on the data of drilling rigs working in Malaysia from 2014 to 2020 as per shown below, it can be concluded that, historically the demand for rig in Malaysia is very dynamic and it was influenced by mainly the brent price albeit a delayed impact. The red line showed the Brent Price.

With the dynamic of the demand, a systematic and well-organized methodology to develop an integrated rig sequence was essential. It is to ensure all rigs were planned accordingly and successfully acquire in time to ensure the projects can be executed as per expectation.

A glimpse on the outcome of having an integrated planning between all the parties related such as host authority, project planners, procurement team, and rig planning team together with a right tool is essential to sequence and plan the projects and the drilling rigs requirement.
Unlocking the True Value of Permanent Acoustic Sensors via Integration in a Digital Field as a Proactive Method of Sand Monitoring in Gas Wells
Authors: Lee Qi Zheng , Yeap Wei Jian , Sidek Sulaiman , Abdul Rahman Hazrina , Kunasekaran Sarran Raj , Ambrose Jonathan , Mackie Alex , Malek Dailami
Published: March 2021

Sand production is one of the operators’ intimidating challenges as the cascading effects can cause significant damages to the surface equipment and often lead to costly clean-up effort. Its effects are further amplified in gas wells with higher gas velocities lead to more detrimental effects on the facilities. Consequently, the facilities will deteriorate, leading to uncontrolled hydrocarbon release which compromise the operation safety considerably. Hence, sand detection devices such as acoustic sensors are extremely crucial to detect sand production as early as possible prior to any undesirable damage. This paper highlights the selection reasoning and advantages of permanent acoustic sensors as well as the method in maximizing the data value through integration with digital field monitoring.

Various sand monitoring equipment are available in the industry and its selection is mainly driven by operators’ purpose with cost-benefit analysis. The multi-disciplinary team collaboratively decided on a holistic approach of utilizing the permanent acoustic sensors to its maximum potential. Integration of permanent acoustic sensors with digital field monitoring further improves the investment return as the sensors can provide real-time sand production data. Effective real time sand monitoring can be performed by both offshore and onshore crews where immediate countermeasure can be deployed if abnormal readings detected.

When handling sand prone wells, proactive measures have been proven to be more effective if compared to reactive measures. Each well production potential can be maximized by installing sand sensors to ensure safe operating envelope without sand production as well as to trigger alarm if sand detected. The key to unlocking the potential is to ensure data is effectively transmitted to the command center and to the office via our digital field system. The operators are also trained on the next course of action such as beaning down the wells to safe operational envelope in case of sand breakthrough. The value of the acoustic sensors outweighs the total cost involved as real-time sand monitoring system helps to safeguard surface facility integrity considerably.
An Impedance Sensor of Water Cut with Three Electrodes and Relative Analysis on Experiment Results
Authors: Yu Chuan , Yang Qinghai , Wei Songbo , Li Ming , Fu Tao
Published: March 2021

Single-layer water cut measurement is of great significance for identifying and shutting off the unwanted water, analyzing oil remained and optimizing production. Currently, however, only the water cut of multilayer mixture can be measured by testing samples taken from wellhead, a way which is widely used in oilfields. That of single-layer fluid cannot be determined yet

To address the problem, this paper puts forward a new impedance sensor that offers long-term online monitoring of single-layer water cut. This sensor is based on the different electrical conductivity of oil and water. It has two layers. The inner one contains three electrodes - two at both sides sending sinusoidal excitation signals and one at the middle receiving signals that have been attenuated by the water-oil medium. With the Maxwell's model of oil-water mixed fluid, the receiver then can measure the water cut online. The outer layer of the sensor is made of PEEK, an insulative protection. In front of the electrodes lies a static mixer which makes the measurement more accurate by fully blending the two media when they flow through the electrodes.

Laboratory tests are carried out with the prototype of the sensor at various oil-water mixing ratios, fluid flow rates, and temperatures. Results show that the average margin of error is within ± 3%. Higher accuracy is seen when high water cut and flow rate enable oil globules to disperse more evenly and the space in between to get wider and the RMS error is less than 2%. If the water cut drops below 80%, the aggregation of the droplets will cause wild fluctuation and more errors in the measurement. In addition, the mineralization of the mixture directly changes its conductivity, which largely impacts the result. Meanwhile, temperature can influence the ionic movement intensity and then alter the conductivity of the medium. Therefore, in practice, the sensor calibration needs to be performed according to the range of medium salinity, and the temperature of the medium is collected in real time for temperature compensation. It is shown that after the adjustment, the water cut measurement results have higher accuracy and consistency.

The impedance sensor can realize online water cut monitoring for a single-layer, indicated by tests. It is more suitable for the increasing high water cut oilfields in that it is more accurate as the water cut grows.
Integrated Coupled Modelling Study to Assess CO2 Sequestration Potential in a Depleted Gas Field
Authors: Azahree Ahmad Ismail , Jaafar Azuddin Farhana , Mohd Ali Siti Syareena , Yakup Muhammad Hamzi , Mustafa Mohd Azlan , Widyanita Ana , Kalita Rintu
Published: March 2021

A depleted gas field is selected as CO2 storage site for future high CO2 content gas field development in Malaysia. The reservoir selected is a carbonate buildup of middle to late Miocene age. This paper describes an integrated modeling approach to evaluate CO2 sequestration potential in depleted carbonate gas reservoir. Integrated dynamic-geochemical and dynamic-geomechanics coupled modeling is required to properly address the risks and uncertainties such as, effect of compaction and subsidence during post-production and injection. The main subsurface uncertainties for assessing the CO2 storage potential are (i) CO2 storage capacity due to higher abandonment pressure (ii) CO2 containment due to geomechanical risks (iii) change in reservoir properties due to reaction of reservoir rock with injected CO2. These uncertainties have been addressed by first building the compositional dynamic model adequately history matched to the production data, and then coupling with geomechanical model and geochemical module during the CO2 injection phase. This is to further study on the trapping mechanisms, caprock integrity, compaction-subsidence implication towards maximum storage capacity and injectivity. The initial standalone dynamic modeling poses few challenges to match the water production in the field due to presence of karsts, extent of a baffle zone between the aquifer and producing zones and uncertainty in the aquifer volume. The overall depletion should be matched, since the field abandonment pressure impacts the CO2 injectivity and storage capacity. A reasonably history matched coupled dynamic-geomechanical model is used as base case for simulating CO2 injection. The dynamic-geomechanical coupling is done with 8 stress steps based on critical pressure changes throughout production and CO2 injection phase. Overburden and reservoir properties has been mapped in Geomechanical grid and was run using two difference constitutive model; Mohr's Coulomb and Modified Cam Clay respectively. The results are then calibrated with real subsidence measurement at platform location. This coupled model has been used to predict the maximum CO2 injection rate of 100 MMscf/d/well and a storage capacity of 1.34 Tscf. The model allows to best design the injection program in terms of well location, target injection zone and surface facilities design. This coupled modeling study is used to mature the field as a viable storage site. The established workflow starting from static model to coupled model to forecasting can be replicated in other similar projects to ensure the subsurface robustness, reduce uncertainty and risk mitigation of the field for CO2 storage site.
The uncertainty relation for joint measurement of position and momentum
Authors: Werner R.F.
Published: March 2021

We prove an uncertainty relation, which imposes a bound on any joint measurement of position and momentum. It is of the form (\Delta P)(\Delta Q)\geq C\hbar, where the `uncertainties' quantify the difference between the marginals of the joint measurement and the corresponding ideal observable. Applied to an approximate position measurement followed by a momentum measurement, the uncertainties become the precision \Delta Q of the position measurement, and the perturbation \Delta P of the conjugate variable introduced by such a measurement. We also determine the best constant C, which is attained for a unique phase space covariant measurement.
New encoding schemes for quantum authentication
Authors: Garcia-Fernandez P. , Fernandez-Martinez E. , Perez E. , Santos D.J.
Published: March 2021

We study the potential of general quantum operations, Trace-Preserving Completely-Positive Maps (TPCPs), as encoding and decoding mechanisms in quantum authentication protocols. The study shows that these general operations do not offer significant advantage over unitary encodings. We also propose a practical authentication protocol based on the use of two successive unitary encodings.
Entanglement tensor for a general pure multipartite quantum state
Authors: Heydari H. , Bjork G.
Published: March 2021

In the black-box model, problems constrained by a `promise' are the only ones that admit a quantum exponential speedup over the best classical algorithm in terms of query complexity. The most prominent example of this is the Deutsch-Jozsa algorithm. More recently, Wim van Dam put forward an algorithm for unstructured problems (i.e., those without a promise). We consider the Deutsch-Jozsa algorithm with a less restrictive (or `broken') promise and study the transition to an unstructured problem. We compare this to the success of van Dam's algorithm. These are both compared with a standard classical sampling algorithm. The Deutsch-Jozsa algorithm remains good as the problem initially becomes less structured, but the van Dam algorithm can be adapted so as to become superior to the Deutsch-Jozsa algorithm as the promise is weakened.
Enantioselective Access to Dialkyl Amines and Alcohols via Ni-Catalyzed Reductive Hydroalkylations
Authors: Wang Shan , Zhang Tian-Yi , Zhang Jian-Xin , Meng Huan , Chen Bi-Hong , Shu Wei
Published: March 2021

Chiral dialkyl amines and alcohols are ubiquitous in pharmaceuticals, pesticides, natural products and fine chemicals, yet difficult to access due to the challenge to differentiate between the spatially and electronically similar alkyl groups. Herein, we report a nickel-catalyzed enantioselective reductive hydroalkylation of enamides and enolates with alkyl halides to afford enantioenriched α-branched aliphatic amines and alcohols in good yields with excellent levels of enantioselectivity. The operationally simple protocol provides a straightforward access to chiral dialkyl amine and alcohol derivatives from simple starting materials with great functional group tolerance.
A Chiral Interlocking Auxiliary Strategy for the Synthesis of Mechanically Planar Chiral Rotaxanes
Authors: de Juan Alberto , Lozano David , Heard Andrew , Jinks Michael , Meijide Suarez Jorge , Goldup Stephen
Published: March 2021

We have serendipitously discovered a combination of reaction partners that function as a “chiral interlocking auxiliary” to both orientate a macrocycle and, effectively, load it onto a new axle. We demonstrate the potential of this finding through the synthesis of a number of targets in high enantiopurity, without separation of stereoisomers, including examples whose axles lack any functional groups that would allow their direct synthesis by other means, so called “impossible” rotaxanes. Intriguingly, by varying the order of bond forming steps, we can effectively choose which end of an axle the macrocycle is loaded onto, allowing the synthesis of both hands of a single target using the same reactions and building blocks.
Validation of Simple Spectrophotometric Method for Determination of Ceftriaxone in Human Plasma
Authors: Luh Putu Mirah Kusuma Dewi  , Djoko Wahyono  , Ika Puspitasari  , Rizka Humardewayanti  , Andi Suhendi
Published: March 2021

The use of the ceftriaxone in the treatment of infections of the urinary tract and respiratory tract associated with sepsis both intravenously and intramuscularly is the primary choice in therapy. To support drug therapy monitoring (TDM), a simple, fast, inexpensive and validated analysis method is needed. The availability of UV-Vis spectrophotometer in almost all clinical laboratories is high, so it can be an alternative to apply in TDM of patients. Accuracy, inter-and intra-day precision, linearity, freeze and thaw stability, and short and long-term stability were parameters determined. The maximum wavelength of ceftriaxone was 272 nm, with linearity at the concentration range of 10-30 µg/mL with a correlation coefficient (r2) of 0.99. The accuracy of the method was studied by recovery study. The result showed that %recovery was found in the range of 94-99% with relative standard deviation (RSD) less than 2%. Intra and inter-day precision were accepted with RSD value of < 2%. The spiked human plasma sample containing ceftriaxone remained stable for 4 hours at room temperature and was stable in storage at -20 ° C for seven days. The method is simple, accurate and inexpensive. The proposed method can be successfully used for the determination of Ceftriaxone sodium in human plasma.
Indications and Prevalence of Hysterectomy for Benign Conditions at a Tertiary Care Hospital in Rural South India–A Descriptive Study
Authors: Chanakya C  , Padmashri P
Published: March 2021

This study aims to assess the indications and prevalence often various types of hysterectomy done for benign diseases. It was a retrospective descriptive study conducted at the Department of Obstetrics and Gynaecology in Saveetha Medical College and Hospital, Thandalam. Data about the hysterectomies done for benign conditions were obtained from January 2019 till December 2019 from the in-hospital medical registry. Demographics, presenting complaints, indications, history, type of hysterectomy and complications were analysed. Amongst the two hundred (200) cases of hysterectomy performed in the year 2019, total abdominal hysterectomy (69%) was the most standard type and Leiomyoma uterus (73.5%) being the most common indication. Bilateral Salphingo-Oophorectomy (55%) was done in most patients, along with hysterectomy. Due to the advent of safer surgical practices, the extent of complications have drastically reduced, excessive bleeding (13.5%) being the most common, surgical site infection (1.5%) and bladder injury (1.5%) were recorded. This study demonstrates that though the incidence of hysterectomy done for benign conditions is decreasing with increasing popularity to go for medical management, women in rural India are still opting for surgical management. This necessitates the need for studies to analyse the psychological aspect governing the acceptance of surgical management in preference to conservative management in these rural women.
Estimation of Cyproheptadine Hydrochloride and Tricholine Citrate Simultaneously in Syrup Dose by Applying Stability Indicating HPLC Methodology
Authors: Kancharla Vijayalakshmi  , Bethapudi Samuel Anand Andrews
Published: March 2021

An stability indicating HPLC methodology for the concurrent estimation of Tricholine citrate (TRC) and Cyproheptadine hydrochloride (CYH) in syrup dose and bulk using Waters column reverse phase C18 (5 µm, 250 mm and 4.6 mm) as stationary phase and 0.1M Na2HPO4  of pH 4.5 and acetonitrile in proportion of 60:40 (v/v) at flow of 1.0 ml/min rate as mobile phase was  reported. The linear scales were 275-825 μg/ml for TRC and 2-6 μg/ml for CYH  with correlation coefficients of 0.9999 for TRC and 0.9997 for CYH. Followed ICH Q2(R1) strategies for validating the suggested method for precision, sensitivity, robustness, specificity, selectivity and accuracy. The measures of LOD and LOQ are 0.023 µg/ml and 0.079 µg/ml for CYH, while for TRC it was 0.565 µg/ml and 1.885 µg/ml, respectively. The precision measures for CYH and TRC were 0.073 and 0.212 relative measured deviation percentage, respectively. The accuracy measures for CYH and TRC were 99.40% and 99.09% mean assay percentiles, respectively. Recovery percentiles measures of CYH and TRC were ranged between 99.48% to 100.35% and 100.38% and 100.41%, respectively. While in degradation investigation, peaks of degraded products are very well differentiated from TRC and CYH peaks suggesting the specificity and stability of suggested methodology. The results permit the application of the proposed  stability indicating HPLC methodology in syrup dose forms.
Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity of Peptides Isolated from Carabao Mango (Mangifera indica) Flesh
Authors: Rojas Trisha , Co Jherome , Bercansil Mia Clare Marie , Dela Cruz Lory Jane , Uy Lawrence Yves , Gamba Ella Mae , Torio Mary Ann
Published: March 2021

Hypertension has been reported as the second major cause of morbidity in the Philippines. One of the mechanisms to control blood pressure is through the inhibition of the angiotensin I-converting enzyme (ACE). This study specifically focused on the determination of ACE inhibitory activities of peptides from ‘Carabao’ mango flesh of three shell colors (SC1, SC3, SC5). The bioactive peptides were obtained upon a series of extraction, purification, and enzymatic hydrolysis steps. Among the undigested and digested crude and purified samples, the highest in vitro ACE inhibition was exhibited by the three-hour digest of SC3 (83.28 ± 0.83%). The most prominent peak from the fractionation of the mixture of peptides in SC3 digest was evaluated for ACE inhibition, and the decrease in activity inferred the synergistic effect of the peptides in exhibiting the inhibitory function. This selected bioactive peptide was revealed to have alanine and phenylalanine as the components, which can possibly be AF – an ACE inhibitory peptide determined from in silico analyses. Meanwhile, assessment of the in vivo antihypertensive activity showed no significant results due to insufficiently administered doses of the samples. Overall, the measured activity of the ACE inhibitory peptides inferred the potential of mango as a functional food in dealing with hypertension.
PENGARUH RELIGIUSITAS ISLAMI TERHADAP PEMAAFAN PADA REMAJA Studi Kasus Di Madrasah Aliyah Negeri III Yogyakarta
Authors: Ru'iya Sutipyo
Published: March 2021

Background: This study was developed based on the recent phenomenon of late adolescents are increasingly experiencing problems in their social life, such as brawls, gang, and the anxiety that causes them to crash while in school. This phenomenon indicates the level of forgivenessÂ  the less. One factor achieving forgiveness is religiosity. Therefore, this study aimed to determine the relationship of religiosity and forgiveness among adolescents especially students of Madrasah Aliyah III Yogyakarta. Objective: Selection of research subjects in adolescent students of Madrasah Aliyah III Yogyakarta is because Madrasah Aliyah III Yogyakarta Yogyakarta is the MAN model, but it had the same problems of students with students in another schools. Methods: This study use a quantitative approach to the subject of the research is a class XI choses by cluster random sampling from some existing classes. Measurement of psychological symptoms using a scale of forgiveness The Heartland Forgiveness Scale (HFS) and religiosity measured by Moslem Religiosity Personality Inventory (MRPI). Both the scale of the researcher adapted from the original source. The number of respondents in this study were 105 students of class XI IPS-1, IPS-2, IPS-3, IPA-1, and IPA-2. Results: Based on the results of data analysis, it is concluded: that there is a positive relationship between the level of Islamic religiosity and forgiveness among adolescents. The higher the level of Islamic religiosity teenagers will be higher and the lower pemaafannya Islamic religiosity teens will be teens forgiveness anyway. The contribution of Islamic religiosity on forgiveness is at 6.1% . Conclusion: From these results, it can be concluded that to improve forgiveness in adolescents, it needs to be improved its Islamic religiosity.
PENDIDIKAN ISLAM DI INDONESIA: RESTROPEKSI DAN PROYEKSI MODERNISASI PENDIDIKAN ISLAM DI INDONESIA
Authors: Sutarman Sutarman
Published: March 2021

Modern Islam Education in Indonesia are generally are influenced by Muhammadiyah organization. As we know that organization of Muhammadiyah has many schools from the Playgroup until the University. Not only Muhammadiyah, NU organization also gives some contribution of education in Indonesia, especially a boarding school. Not only both of the private organization which give some contributions in education, there are also manyÂ  pionirs of Islamic education in Indonesia that have given the contributions, as like Ki Hajar Dewantara, Harun Nasution, Mukti Ali,Â  Malik Fajar, etc. They dreamed to the generation that would combine intellectualâ€ enlightenmentâ€ with pure spirituality, wisdom, and continuous activism. Being extraordinarily knowledgeable in religious and social sciences and familier with principle of material sciences. So, the equilibrium for society are able to be gotten.
PEMBELAJARAN BERBASIS KOMPUTE
Authors: Sarjiati Sarjiati
Published: March 2021

In this global era , the more rapid development of science , which is characterized by the rapid advancement of information and communication technology world , encourage changes in education. Teachers (educators) are no longer present as the sole source of knowledge in a learning process . Therefore , an educator (teacher) if you want to keep survive in playing its role in the process of learning activities , they should have the creativity , in making the changes (innovations) , approaches , methods in the process of teaching and learning activities . In order to facilitate this learning , then teachers (educators) need to have a creative and innovative spirit . Therefore , a teacher is not enough just to master the competency (cognitive) alone, but also have to master information technology as a medium of communication , computer-based learning interesting and fun
IMPLEMENTASI TOTAL QUALITY MANAJEMEN DI SMP MUHAMMADIYAH I DEPOK SLEMAN
Authors: Hamidi Nur
Published: March 2021

Entering the past decade, the issue of quality has always been the talk of the actual, especially in the context of education management. Recognized or not, the quality of Islamic education institutions are still largely under the quality of education in general. Various attempts have been made and many of the concepts that have been applied, but everything seemed not bring significant improvement. "Total Quality Management (TQM) or Integrated Quality Management (MMT) as an effort to improve the quality of education in Islamic educational institutions. Although at first the concept of MMT is only known in the industry, but the amazing success invite the interest of education experts, 3 to study it more deeply, formulate operational patterns of adoption, and to create a model in teknical to apply. This research was conducted in SMP Muhammadiyah I Depok Sleman Yogyakarta. Consideration is SMP Muhammadiyah I Gurgaon is one of the Islamic educational institutions (schools distinctively Islamic) 5 formal mission has always been to apply concepts of Quality Management (TQM). This study resulted in that SMP Muhammadiyah I Depok already implementing Total Quality Management in the management of education. However, the application of Total Quality Management in SMP Muhammadiyah I Depok can be said is not fully maximized, in the sense that there are still some things that need to be evaluated together.
KONSEP ILMU DALAM PANDANGAN ISLAM
Authors: Shomiyatun Shomiyatun
Published: March 2021

The concept of science in term of Islam is ulamaâ€™s (Islamic scientistsâ€™) thought on understanding, viewing, locating, classifying, dan treating science. It includes what science is obliged to study and to practice and what science is not. It also includes how to view useful science and what its criteria are. The method of research is qualitative library one supported with observation. The objective is to convey the importance of ulamaâ€™s concept of science. This is education which should continuously be given and kept going to stimulate, guide and teach students so that they have abilities, skills and complete personalities and science lights and guides them to usefull lives. That is important because science, technology and religion make life much easy. However behind the easyness various big problems come to threaten people when they are careless and wrong in understanding the concept of science and technology. The developed study and classification of science help students learn it easily becase they have limited time. Moslems are obliged to have Islamic concept of science and to study and to practice it. The classification of science without relevant concept is dangerous. The concept of Islamic religious and wordly sciences is not appropriate. The religious science is Alquran and Hadits while worly one is natural science. The concept is dichotomy and shows that natural science is not a part of Islamic science and that Islamic science does not develop as the natural one. The article critizes the classification of natural and Islamic sciences. The classification is wrong. Islam teaches that science is integrated and useful for human being and nature. The wrong concept and classification result fatal errors and should be critized and corrected.