Large Balloons Research Articles

Age and gravitational separation of the stratospheric air over Indonesia

Abstract. The gravitational separation of major atmospheric components, in addition to the age of air, would provide additional useful information about stratospheric circulation. However, observations of the age of air and gravitational separation are still geographically sparse, especially in the tropics. In order to address this issue, air samples were collected over Biak, Indonesia in February 2015 using four large plastic balloons, each loaded with two compact cryogenic samplers. With a vertical resolution of better than 2 km, air samples from seven different altitudes were analyzed for CO2 and SF6 mole fractions, δ15N of N2, δ18O of O2, and δ(Ar∕N2) to examine the vertically dependent age and gravitational separation of air in the tropical tropopause layer (TTL) and the equatorial stratosphere. By comparing their measured mole fractions with aircraft observations in the upper tropical troposphere, we have found that CO2 and SF6 ages increase gradually with increasing altitude from the TTL to 22 km, and then rapidly from there up to 29 km. The CO2 and SF6 ages agree well with each other in the TTL and in the lower stratosphere, but show a significant difference above 24 km. The average values of δ15N of N2, δ18O of O2, and δ(Ar∕N2) all show a small but distinct upward decrease due to the gravitational separation effect. Simulations with a two-dimensional atmospheric transport model indicate that the gravitational separation effect decreases as tropical upwelling is enhanced. From the model calculations with enhanced eddy mixing, it is also found that the upward increase in air age is magnified by horizontal mixing. These model simulations also show that the gravitational separation effect remains relatively constant in the lower stratosphere. The results of this study strongly suggest that the gravitational separation, combined with the age of air, can be used to diagnose air transport processes in the stratosphere.

Dynamics modeling of large stratospheric balloons based on attitude motion measurement

Dynamics modeling of large stratospheric balloons based on attitude motion measurement

Ballooning for Biologists: Mission Essentials for Flying Life Science Experiments to Near Space on NASA Large Scientific Balloons

Despite centuries of scientific balloon flights, only a handful of experiments have produced biologically-relevant results. Yet unlike orbital spaceflight, it is much faster and cheaper to conduct biology research with balloons, sending specimens to the near space environment of Earth's stratosphere. Samples can be loaded the morning of a launch and sometimes returned to the laboratory within one day after flying. The National Aeronautics and Space Administration (NASA) flies large, unmanned scientific balloons from all over the globe, with missions ranging from hours to weeks in duration. A payload in the middle portion of the stratosphere (~35 km above sea level) will be exposed to an environment similar to the surface of Mars: temperatures generally around -36 °C, atmospheric pressure at a thin 1 kPa, relative humidity levels < 1%, and a harsh illumination of ultraviolet (UV) and cosmic radiation levels (about 100 W/m2 and 0.1 mGy/d, respectively) that can be obtained nowhere else on the surface of the Earth, including environmental chambers and particle accelerator facilities attempting to simulate space radiation effects. Considering the operational advantages of ballooning and the fidelity of space-like stressors in the stratosphere, researchers in aerobiology, astrobiology, and space biology can benefit from balloon flight experiments as an intermediary step on the extraterrestrial continuum (ground, low Earth orbit, and deep space studies). Our review targets biologists with no background or experience in scientific ballooning. We will provide an overview of large balloon operations, biology topics that can be uniquely addressed in the stratosphere, and a roadmap for developing payloads to fly with NASA.

Over-expansion of drug-eluting stents in patients with left main coronary artery disease: An invivo study.

ObjectiveWe aimed to determine the capacity of drug-eluting stent (DES) over-expansion in left main coronary artery disease.MethodsLeft main interventions with the largest available DES platforms (4.0 mm) and post-dilation performed with large non-compliant balloons (≥ 4.5 mm) were included. Maximal stent diameter (mm) and area (mm2) were measured using post-intervention intravascular ultrasound (IVUS). Stent diameter and area were calculated with the balloon diameter and inflation pressure. The diameter and area expansion indices were defined as follows: maximal/calculated stent diameter and maximal/calculated stent area, respectively.ResultsTwenty-three consecutive patients were included. The maximal stent diameter was 4.40 mm (4.30–4.80 mm), and 22 of 23 patients showed a diameter expansion index greater than 0.90. The area expansion index was 0.862. The expansion index < 0.85 group had a significantly higher percentage of calcification ≥ 90° on IVUS than did the expansion index ≥ 0.85 group (72.7% versus 16.7%, P = 0.007). One stent fracture occurred during over-expansion and one ischemic event occurred during follow-up.ConclusionsDESs with a nominal diameter of 4.0 mm can be effectively over-expanded in left main coronary artery disease. Achievement of predicted stent area can be affected by calcification.

Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching

Abstract. MIPAS-Envisat is a satellite-borne sensor which measured vertical profiles of a wide range of trace gases from 2002 to 2012 using IR emission spectroscopy. We present geophysical validation of the MIPAS-Envisat operational retrieval (version 6.0) of N2O, CH4, CFC-12, and CFC-11 by the European Space Agency (ESA). The geophysical validation data are derived from measurements of samples collected by a cryogenic whole air sampler flown to altitudes of up to 34 km by means of large scientific balloons. In order to increase the number of coincidences between the satellite and the balloon observations, we applied a trajectory matching technique. The results are presented for different time periods due to a change in the spectroscopic resolution of MIPAS in early 2005. Retrieval results for N2O, CH4, and CFC-12 show partly good agreement for some altitude regions, which differs for the periods with different spectroscopic resolution. The more recent low spectroscopic resolution data above 20 km altitude show agreement with the combined uncertainties, while there is a tendency of the earlier high spectral resolution data set to underestimate these species above 25 km. The earlier high spectral resolution data show a significant overestimation of the mixing ratios for N2O, CH4, and CFC-12 below 20 km. These differences need to be considered when using these data. The CFC-11 results from the operation retrieval version 6.0 cannot be recommended for scientific studies due to a systematic overestimation of the CFC-11 mixing ratios at all altitudes.

Classic crush and DK crush stenting techniques.

Clinical data have supported the advantages of the double kissing (DK) crush technique, which consists of stenting the side branch (SB), balloon crush, first kissing, stenting the main vessel (MV) and final kissing balloon inflation, for complex coronary bifurcation lesions compared to other stenting techniques. Careful rewiring from the proximal cell of the MV stent to make sure the wire is in the true lumen of the SB stent is key to acquiring optimal angiographic results. Balloon anchoring from the MV, alternative inflation and each kissing inflation using large enough non-compliant balloons at high pressure, and the proximal optimisation technique are mandatory to improve both angiographic and clinical outcomes. Stratification of a given bifurcation lesion is recommended before decision making.

Commentary on “The Effect of Deep Venous Stenting on Healing of Lower Limb Venous Ulcers”

It is now well accepted that placement of venous stents is the “method of choice” for treatment of pelvic venous outflow obstruction. George et al.1George R. Verma H. Ram B.L. Tripathi R.K. The effect of deep venous stenting on healing of lower limb venous ulcers.Eur J Vasc Endovasc Surg. 2014; x (xx–xx)Google Scholar performed computed tomography (CT) venography in patients with persistent venous leg ulcers after failed conservative treatment and superficial venous interventions. The authors proceeded with transfemoral/ascending phlebography when CT-venography findings suggested obstruction. Obstruction was found in 38 patients (44 limbs) and stents were placed. The actual number of patients tested to find these patients is not given. The endpoint was healing of the ulcer. The cumulative freedom from ulcer after stenting was at 2 years approximately 60%. This was achieved despite the presence of perforator insufficiency, deep reflux, and significant saphenous incompetence in 90%, 26%, and 10%, respectively, of patients with pre-intervention duplex scanning. Patients with healed ulcers continued to stay healed at a cumulative rate of approximately 83% at 2 years. This findings are line with the results of others as referred to in the study and point to the importance of iliofemoral venous outflow obstruction in the pathophysiology of venous ulcer formation. The prevalence of outflow obstruction in patients with recalcitrant venous ulcers is still unknown. It may be hard to decide since non-thrombotic iliac vein lesions are ubiquitous and we still don't know at what degree a venous stenosis is hemodynamically significant. I agree with the authors that it certainly appears to be worthwhile to search for an iliofemoral outflow obstruction in patients with leg ulcers, which are difficult to heal or recur with other treatment. The authors don't inform us what they considered a significant obstruction. In absence of lack of hemodynamic information, most would consider to treat an obstruction with a minimal diameter stenosis of >50% based on acceptable clinical outcome in patients stented with this criterion. Although very helpful in diagnosis and accurate placing of stents, intravascular ultrasound is unfortunately often too expensive to use. The authors used a so-called “trial angioplasty” or “diagnostic ballooning” when no obvious obstruction was seen. However, there is no information in the study what degree of “waisting” resulted in an intervention. The method has not been validated. I would caution those that use this technique. Large diameter balloons (especially if high pressure balloons are used) placed in the angle at the iliac confluence or at the internal iliac venous inflow may produce a false waist with the unfolding of the balloon. An accurate hemodynamic test for outflow obstruction, preferably non-invasive, needs to be developed to establish a defined indication for stenting. Until then awareness of the importance of obstruction, clinical signs and symptoms, and morphological criteria will have to do. A reduction of the ulcer size is not in itself an accepted endpoint, but could be used within a Venous Clinical Severity Score. A proper CEAP classification of the study patients was not given. It is difficult to analyze the reasons for lack of healing and recurrence of ulcers in this small amount of material. None was found. The presence of axial deep reflux, development of “new” reflux, occlusion of the stent system, recurrence of deep vein thrombosis, incompliance with concomitant compression therapy, etc., have certainly been pointed out in larger studies by others. The Effect of Deep Venous Stenting on Healing of Lower Limb Venous UlcersEuropean Journal of Vascular and Endovascular SurgeryVol. 48Issue 3PreviewTo report the outcomes of endovascular interventions on deep veins in patients with venous ulcers (C6). Full-Text PDF Open ArchiveRe. “The Effect of Deep Venous Stenting on Healing of Lower Limb Venous Ulcers”European Journal of Vascular and Endovascular SurgeryVol. 48Issue 6PreviewWe read with interest Peter Neglen's commentary on our paper.1,2 Full-Text PDF Open Archive

The design and use of plastic balloons for stratospheric research in India

Plastic balloon flying has been developed at the Tata Institute of Fundamental Research as a research technique which has a number of important applications in India: (a) cosmic ray studies; (b) air sampling in the stratosphere for fall-out measurements; (c) meteorological investigations; (d) astronomical observations; (e) defence research. Comparatively little work has been done till now in these fields at equatorial latitudes, particularly at stratospheric altitudes. Large plastic balloons with volumes of the order of half a million cubic feet, and more, have been constructed by heat welding polyethylene sheeting 0.0015 thick. With these balloons, successful level flights at altitudes of 110,000 ft. have been achieved; in some cases, individual loads weighing a hundred pounds have been carried up. The most serious problem encountered is the extremely low temperature(about-85DegreeC), of the tropopause at the equatorial latitudes; all known plastics for balloon manufacture become brittle at these low temperatures. To overcome this, dark fabrics have been employed so that the material is heated by solar radiation. The plastic sheeting employed is extruded in India to balloon specifications from chosen polymers. The low temperatures and the turbulent conditions that prevail in the atmosphere at low latitudes present problems in balloon flying which are different from those encountered at high latitudes present in balloon flying which are different from those encountered at high latitudes. The techniques employed, the design of the balloons, and their performance under these conditions are discussed.

Insights into longitudinal stent elongation phenomenon after high pressure additional post stent dilatation from bench testing

Objective: To evaluate how post stent dilatation with large balloons has impact on stent elongation. Methods: Four kind of stents (Fig1-b) were deployed into a silicon tube model; 10mm of one side of the stent was attached to the model wall and 10mm on the opposite side of the stent was free from the vessel wall (Fig1-a). Then, in each model, post stent dilatation (PD) (Fig1-b) was performed with four different kind of 3.5mm balloons at nominal (NP) and rated balloon pressure (RP). A total of 16 stents were tested, and difference of degree of stent elongation in the stent portion which was free from the wall (delta stent length) was measured and compared among different kind of stents and different kind of balloons. Furthermore, four kind of deployed stents were also dilated three times at RP to evaluate the impact of repeated dilataton on stent elongation. Result: Stent elongation was observed in all models. Delta stent length before and after PD at NP and RP were 0.41±0.15mm and 1.15±0.37mm, respectively. Compared with different four kind of stents, there was no significant difference in delta stent length before and after PD at both NP and RP (p=0.58, 0.96, respectively), however compared with different four kind of post dilatation balloons, significant difference in delta stent length before and after PD was observed at both NP and RP (p=0.016, <0.001, respectively). Moreover, repeated post dilatation led to delta stent length was getting longer in all stents, and the degree may also depends on difference kind of stents. ![Figure][1] Conclusion: Stent elongation after post stent dilatation was observed in this ex vivo model which may be mainly influenced by the type of post dilatation balloons and dilatation pressure. Repeated post dilatation may have an effect on aggravation of stent elongation. [1]: pending:yes

Dipeptidyl‐peptidase‐like proteins cast in a new role: enabling scorpion toxin block of A‐type K+ channels

Dipeptidyl‐peptidase‐like proteins cast in a new role: enabling scorpion toxin block of A‐type K⁺ channels

Efficacy and safety of sphincterotomy with sphincteroplasty using large caliber balloons in the treatment of choledocholithiasis with extraction difficulties

Introduction: Endoscopic retrograde cholangiopan-creatography (ERCP) with endoscopic sphincterotomy (ES) is the most widely used technique for treating choledocholithiasis. In some cases, due to anomalies of the papilla or the presence of large or multiple calculi, additional maneuvers are needed to remove the stones. The present study investigates the efficacy and safety of ES with sphincteroplasty (SP) in the management of choledocholithiasis with extraction difficulties. Patients and Methods: A prospective study was made of 153 patients with choledocholithiasis subjected to ERCP. Fifty-two patients underwent ES with SP, while 101 were subjected only to ES. The two groups were compared in terms of age, gender, percentage cannulation, presence of papilla alterations, large or multiple stones, success in stone removal and complications (acute pancreatitis, bleeding and perforation). In the ES with SP group, we moreover recorded the diameters of the balloons employed (10-18 mm). Results: There were no significant differences between the groups in the stone extraction success rate (94.23% in the ES with SP group versus 97.03% in the ES group) or in the appearance of complications (3.8% in the ES with SP group versus 2.7% in the ES group). The presence of difficult papillae, and of multiple or large stones was significantly greater in the ES with SP group. The diameter of the balloon was not associated with the appearance of complications. Conclusion: Endoscopic sphincterotomy with sphincteroplasty is effective and safe in the treatment of choledocholithiasis with extraction difficulties.

Lifting options for stratospheric aerosol geoengineering: advantages of tethered balloon systems

The Royal Society report 'Geoengineering the Climate' identified solar radiation management using albedo-enhancing aerosols injected into the stratosphere as the most affordable and effective option for geoengineering, but did not consider in any detail the options for delivery. This paper provides outline engineering analyses of the options, both for batch-delivery processes, following up on previous work for artillery shells, missiles, aircraft and free-flying balloons, as well as a more lengthy analysis of continuous-delivery systems that require a pipe connected to the ground and supported at a height of 20 km, either by a tower or by a tethered balloon. Towers are shown not to be practical, but a tethered balloon delivery system, with high-pressure pumping, appears to have much lower operating and capital costs than all other delivery options. Instead of transporting sulphuric acid mist precursors, such a system could also be used to transport slurries of high refractive index particles such as coated titanium dioxide. The use of such particles would allow useful experiments on opacity, coagulation and atmospheric chemistry at modest rates so as not to perturb regional or global climatic conditions, thus reducing scale-up risks. Criteria for particle choice are discussed, including the need to minimize or prevent ozone destruction. The paper estimates the time scales and relatively modest costs required if a tethered balloon system were to be introduced in a measured way with testing and development work proceeding over three decades, rather than in an emergency. The manufacture of a tether capable of sustaining the high tensions and internal pressures needed, as well as strong winds, is a significant challenge, as is the development of the necessary pumping and dispersion technologies. The greatest challenge may be the manufacture and launch of very large balloons, but means have been identified to significantly reduce the size of such balloons or aerostats.

Operation Outward [History

Most students of world War II are aware of the thousands of barrage balloons that Britain employed throughout the war to help protect cities, ports, and other important targets from low-flying Luftwaffe dive bombers and fighters. These large gas balloons measured about 64 ft (19.5 m) long by 34 ft (10.4 m) in diameter and were tethered to the ground by steel cables attached to winches and rose to heights of up to 5,000 ft (1,524 m).

First implantation of the CE-marked transcatheter Sapien pulmonic valve in Europe

First implantation of the CE-marked transcatheter Sapien pulmonic valve in Europe

Effects of large-balloon dilation on the major duodenal papilla and the lower bile duct: histological evaluation by using an ex vivo adult porcine model

Several articles have reported the usefulness of large-balloon dilation after endoscopic sphincterotomy in removing bile duct stones. Its histological effect on the duodenal papilla and the lower bile duct, however, is not well established. To elucidate the histological consequence of large-balloon dilation. Animal experiment. A referral center. After the evaluation of normal anatomy of the major duodenal papilla and the lower bile duct in resected specimens from pigs, large-balloon dilation (12-20 mm) after small sphincterotomy was performed, and serial tissue sections were assessed for morphological changes. Macroscopic and microscopic findings of the duodenal papilla and the lower bile duct after large balloon dilation, with special interest in ductal wall disruption and perforation. The porcine specimens were comparable in size to humans. Balloons with diameters 12 mm or larger caused disruption of the ductal walls, and those 15 mm or larger resulted in perforation of the surrounding adipose tissue. The frequency of disruption and perforation increased in proportion to the balloon diameters. Other sequelae including hemorrhage, pancreatitis, acute inflammatory changes, and late fibrosis could not be investigated in our ex vivo porcine model. Dilation with large balloons can tear the bile duct wall and cause potential impairment of sphincter function and overdilation of small extrahepatic bile ducts.

Simple method to predict balloon shape

A numerical scheme to predict the shape of large scientific balloons is described. The method ignores elastic deformation and asymmetric folding. Results are presented for geometries where all the tension in the balloon fabric is carried meridionally and the circumferential stresses are assumed to be zero, during ascent, as well as at the design float altitude. Some results with envelopes with non-zero circumferential stresses and with caps fitted are also given. Brief comparison with the results of more complex numerical models, reported by other workers, suggests that the method yields nearly identical geometric solutions.

Current Developments and Future Plans at NBF@Hyderabad and Prospects for Long Duration Balloon Flights

Established in 1971, National Balloon Facility at Hyderabad is a unique centre which offers complete solution in scientific ballooning for near space access using high altitude balloons. It combines both, in house balloon production and complete flight and recovery support to the experimenters. The balloon facility is also mandated to perform necessary research and development to meet future needs in scientific ballooning and lighter than air systems. The balloon flights conducted by the facility during the last few years are of two types (a) Large volume balloons up to 740,000 m3 with heavy payloads for astronomy experiments and (b) Smaller balloons using lighter payloads for atmospheric sciences and the wind sounding flights up to 43 km altitude. At present, we are involved in the development of a portable telemetry, tracking and telecommand sub-system for remote operation and data link for long duration flights over the continent or the polar missions. Efforts are also on for the design and development of material and envelope design for high altitude platforms for the study of aerosols and trace gases. In this paper I will present details of our present activities and also outline our plans for the future directions.

A new balloon base in Japan

Since 1971, numerous balloons have been launched from the Japanese balloon base, the Sanriku Balloon Center (SBC). Through these years, balloon technologies have been developed continuously and many scientific achievements have resulted. Recently, however, because of the limited area of the launching pad of the SBC, we have been faced with the difficulty of safely launching large balloons. To solve this issue, we decided to move the balloon base from the SBC to the Taiki Aerospace Research Field (TARF) in northern Japan. The TARF had an existing huge hanger and a paved launch pad capable of being utilised for balloon operations. To evolve the TARF into a new balloon base, new balloon facilities have been constructed at the TARF and equipment was transferred from the SBC to the TARF during July 2007 and March 2008. The SBC was closed in September 2007, and the new base became operational in May 2008. The new base at the TARF is designed to launch larger balloons with greater safety and to perform balloon operations more effectively than ever before. In the summer of 2008, we carried out the first series of the balloon campaign at the TARF, and succeeded in two engineering flights of stratospheric balloons. By the success of these flights, we have verified that the whole system of the new balloon base is well established.

Dilatación de la papila de Vater con balón de gran diámetro para la extracción de coledocolitiasis

To assess the efficacy and safety of dilatation of the papilla of Vater with large balloons for the treatment of choledocolithiasis in patients with difficult or risky extraction due to stone characteristics or peripapillary anatomy. Prospective. This study includes 93 patients in whom large-balloon dilation was performed between June 2005 and January 2008. Patients had multiple large stones, tapered distal CBD (common bile duct), peri-/intra-diverticular papilla, and previous sphincterotomy or Billroth-II surgery. A controlled radial expansion (CRE) balloon with a diameter range of 12-20 mm was used. Stone removal was achieved in a single session in all patients (100 %). Most procedures (86%) did not require an extended exploration time. Mechanical lithotripsy was needed in 3.2 % of cases. There were two mild complications (2.1%). Hyperamilasemia was detected in 16% of patients. Papillary dilation with a large balloon is an effective, safe, and easy technique for the retrieval of difficult common bile-duct stones. The procedure neither adds time to the exploration, nor increases complications, and obviates the need for mechanical lithotripsy in a majority of patients.

Technical Note: Validation of Odin/SMR limb observations of ozone, comparisons with OSIRIS, POAM III, ground-based and balloon-borne instruments

Abstract. The Odin satellite carries two instruments capable of determining stratospheric ozone profiles by limb sounding: the Sub-Millimetre Radiometer (SMR) and the UV-visible spectrograph of the OSIRIS (Optical Spectrograph and InfraRed Imager System) instrument. A large number of ozone profiles measurements were performed during six years from November 2001 to present. This ozone dataset is here used to make quantitative comparisons with satellite measurements in order to assess the quality of the Odin/SMR ozone measurements. In a first step, we compare Swedish SMR retrievals version 2.1, French SMR ozone retrievals version 222 (both from the 501.8 GHz band), and the OSIRIS retrievals version 3.0, with the operational version 4.0 ozone product from POAM III (Polar Ozone Atmospheric Measurement). In a second step, we refine the Odin/SMR validation by comparisons with ground-based instruments and balloon-borne observations. We use observations carried out within the framework of the Network for Detection of Atmospheric Composition Change (NDACC) and balloon flight missions conducted by the Canadian Space Agency (CSA), the Laboratoire de Physique et de Chimie de l\\'{}Environnement (LPCE, Orléans, France), and the Service d'Aéronomie (SA, Paris, France). Coincidence criteria were 5° in latitude×10° in longitude, and 5 h in time in Odin/POAM III comparisons, 12 h in Odin/NDACC comparisons, and 72 h in Odin/balloons comparisons. An agreement is found with the POAM III experiment (10–60 km) within −0.3±0.2 ppmv (bias±standard deviation) for SMR (v222, v2.1) and within −0.5±0.2 ppmv for OSIRIS (v3.0). Odin ozone mixing ratio products are systematically slightly lower than the POAM III data and show an ozone maximum lower by 1–5 km in altitude. The comparisons with the NDACC data (10–34 km for ozonesonde, 10–50 km for lidar, 10–60 for microwave instruments) yield a good agreement within −0.15±0.3 ppmv for the SMR data and −0.3±0.3 ppmv for the OSIRIS data. Finally the comparisons with instruments on large balloons (10–31 km) show a good agreement, within −0.7±1 ppmv. The official SMR v2.1 dataset is consistent in all altitude ranges with POAM III, NDACC and large balloon-borne instruments measurements. In the SMR v2.1 data, no different systematic error has been found in the 0–35km range in comparison with the 35–60 km range. The same feature has been highlighted in both hemispheres in SMR v2.1/POAM III intercomparisons, and no latitudinal dependence has been revealed in SMR v2.1/NDACC intercomparisons.